kernel: Make the patches apply on top of 4.19

This makes the patches which were just copied in the previous commit
apply on top of kernel 4.19.

The patches in the backports-4.19 folder were checked if they are really
in kernel 4.19 based on the title and only removed if they were found in
the upstream kernel.

The following additional patches form the pending folder went into
upstream Linux 4.19:
pending-4.19/171-usb-dwc2-Fix-inefficient-copy-of-unaligned-buffers.patch
pending-4.19/190-2-5-e1000e-Fix-wrong-comment-related-to-link-detection.patch
pending-4.19/478-mtd-spi-nor-Add-support-for-XM25QH64A-and-XM25QH128A.patch
pending-4.19/479-mtd-spi-nor-add-eon-en25qh32.patch
pending-4.19/950-tty-serial-exar-generalize-rs485-setup.patch
pending-4.19/340-MIPS-mm-remove-mips_dma_mapping_error.patch

Bigger changes were introduced to the m25p80 spi nor driver, as far as I
saw it in the new code, it now has the functionality provided in this
patch:
pending-4.19/450-mtd-m25p80-allow-fallback-from-spi_flash_read-to-reg.patch

Part of this patch went upstream independent of OpenWrt:
hack-4.19/220-gc_sections.patch
This patch was reworked to match the changes done upstream.

The MIPS DMA API changed a lot, this patch was rewritten to match the
new DMA handling:
pending-4.19/341-MIPS-mm-remove-no-op-dma_map_ops-where-possible.patch

I did bigger manual changes to the following patches and I am not 100% sure if they are all correct:
pending-4.19/0931-w1-gpio-fix-problem-with-platfom-data-in-w1-gpio.patch
pending-4.19/411-mtd-partial_eraseblock_write.patch
pending-4.19/600-netfilter_conntrack_flush.patch
pending-4.19/611-netfilter_match_bypass_default_table.patch
pending-4.19/670-ipv6-allow-rejecting-with-source-address-failed-policy.patch
hack-4.19/211-host_tools_portability.patch
hack-4.19/221-module_exports.patch
hack-4.19/321-powerpc_crtsavres_prereq.patch
hack-4.19/902-debloat_proc.patch

This is based on patchset from Marko Ratkaj <marko.ratkaj@sartura.hr>

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

target/linux/generic/hack-4.19/221-module_exports.patch

@@ -27,27 +27,27 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +#define SYMTAB_DISCARD_GPL
 +#endif
 +
- #include <linux/export.h>
- 
  /* Align . to a 8 byte boundary equals to maximum function alignment. */
-@@ -341,14 +351,14 @@
+ #define ALIGN_FUNCTION()  . = ALIGN(8)
+ 
+@@ -372,14 +382,14 @@
  	/* Kernel symbol table: Normal symbols */			\
  	__ksymtab         : AT(ADDR(__ksymtab) - LOAD_OFFSET) {		\
- 		VMLINUX_SYMBOL(__start___ksymtab) = .;			\
+ 		__start___ksymtab = .;					\
 -		KEEP(*(SORT(___ksymtab+*)))				\
 +		SYMTAB_KEEP						\
- 		VMLINUX_SYMBOL(__stop___ksymtab) = .;			\
+ 		__stop___ksymtab = .;					\
  	}								\
  									\
  	/* Kernel symbol table: GPL-only symbols */			\
  	__ksymtab_gpl     : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) {	\
- 		VMLINUX_SYMBOL(__start___ksymtab_gpl) = .;		\
+ 		__start___ksymtab_gpl = .;				\
 -		KEEP(*(SORT(___ksymtab_gpl+*)))				\
 +		SYMTAB_KEEP_GPL						\
- 		VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .;		\
+ 		__stop___ksymtab_gpl = .;				\
  	}								\
  									\
-@@ -410,7 +420,7 @@
+@@ -441,7 +451,7 @@
  									\
  	/* Kernel symbol table: strings */				\
          __ksymtab_strings : AT(ADDR(__ksymtab_strings) - LOAD_OFFSET) {	\
@@ -56,7 +56,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	}								\
  									\
  	/* __*init sections */						\
-@@ -793,6 +803,8 @@
+@@ -841,6 +851,8 @@
  	EXIT_TEXT							\
  	EXIT_DATA							\
  	EXIT_CALL							\
@@ -67,8 +67,8 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	}
 --- a/include/linux/export.h
 +++ b/include/linux/export.h
-@@ -60,12 +60,19 @@ extern struct module __this_module;
- #define __CRC_SYMBOL(sym, sec)
+@@ -74,12 +74,19 @@ struct kernel_symbol {
+ };
  #endif
  
 +#ifdef MODULE
@@ -82,15 +82,15 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	extern typeof(sym) sym;						\
  	__CRC_SYMBOL(sym, sec)						\
  	static const char __kstrtab_##sym[]				\
--	__attribute__((section("__ksymtab_strings"), aligned(1)))	\
+-	__attribute__((section("__ksymtab_strings"), used, aligned(1)))	\
 +	__attribute__((section("__ksymtab_strings"			\
-+	  __EXPORT_SUFFIX(sym)), aligned(1)))				\
- 	= VMLINUX_SYMBOL_STR(sym);					\
- 	static const struct kernel_symbol __ksymtab_##sym		\
- 	__used								\
++	  __EXPORT_SUFFIX(sym)), used, aligned(1)))			\
+ 	= #sym;								\
+ 	__KSYMTAB_ENTRY(sym, sec)
+ 
 --- a/scripts/Makefile.build
 +++ b/scripts/Makefile.build
-@@ -432,7 +432,7 @@ targets += $(extra-y) $(MAKECMDGOALS) $(
+@@ -408,7 +408,7 @@ targets += $(extra-y) $(MAKECMDGOALS) $(
  # Linker scripts preprocessor (.lds.S -> .lds)
  # ---------------------------------------------------------------------------
  quiet_cmd_cpp_lds_S = LDS     $@