armvirt: add EFI support

EFI booting is used on newer machines compatible with the
Arm SystemReady specifications.

This commit restructures armvirt into a more 'generic'
target similar to x86.

See https://github.com/openwrt/openwrt/pull/4956
for a history of this port.

Signed-off-by: Mathew McBride <matt@traverse.com.au>

target/linux/armvirt/Makefile

@@ -6,7 +6,7 @@ include $(TOPDIR)/rules.mk
 
 BOARD:=armvirt
 BOARDNAME:=QEMU ARM Virtual Machine
-FEATURES:=fpu pci rtc usb
+FEATURES:=fpu pci pcie rtc usb boot-part rootfs-part
 FEATURES+=cpiogz ext4 ramdisk squashfs targz
 
 KERNEL_PATCHVER:=5.15
@@ -15,5 +15,8 @@ KERNEL_TESTING_PATCHVER:=6.1
 include $(INCLUDE_DIR)/target.mk
 
 DEFAULT_PACKAGES += mkf2fs e2fsprogs
+# blkid used for resolving PARTUUID
+# in sysupgrade
+DEFAULT_PACKAGES += blkid
 
 $(eval $(call BuildTarget))