ramips: add support for Mikrotik LtAP-2HnD

Mikrotik LtAP-2HnD is a outdoor/automotive WLAN 4 router with integrated GPS
receiver and two mPCIe slots.

Specifications:
* SoC: MT7621A
* RAM: 128 MiB Nanya NT5CC64M16GP-DI
* Flash: 16 MiB winbond W25Q128JV
* WLAN:
  * Atheros AR9382 with power amplifier SKY 85330 (2x2 internal antennas,
    with RF switches for external connectors)
* Ethernet: 1 Gbps, single port
* USB Host: USB 2.0 Speeds
* Serial: 115200 baud
* LEDs: Power, System, GPS, 5* RSSI
*  mPCIe:
   * miniPCIe slot 1: PCIe and USB 2.0 Host (via switch shared with USB Host)
   * miniPCIe slot 2: USB 2.0 and 3.0
* SIM Cards:
  * Slot 1 Connected to mPCIe slot 1
  * Slot 2 and 3 connected to mPCIe slot 2 via switch
* GPS: MTK 3333 on serial port 2 (/dev/ttyS1), 115200 baud and PPS on gpio 14

gpios are exposed to /sys/class/gpio:

* usb-select: swithes USB 2.0 interface between external port and internal
mPCIe slot 1 default is the external USB interface
* gps-reset: resets the GPS interface chip
* sim-select: switches between sim slot 2 and 3 connected to mPCIe slot 2
* gps-ant-select: switches GPS antenna between internal antenna and SMA
connected antenna
* lte-reset: resets mPCIe slot 2

Flashing:
 TFTP boot initramfs image and then perform sysupgrade. Follow common
 MikroTik procedure as in https://openwrt.org/toh/mikrotik/common.

Signed-off-by: Arne Zachlod <arne@nerdkeller.org>

target/linux/ramips/mt7621/base-files/etc/board.d/01_leds

@@ -95,6 +95,7 @@ linksys,ea8100-v2)
 mikrotik,routerboard-760igs)
 	ucidef_set_led_netdev "sfp" "SFP" "blue:sfp" "sfp"
 	;;
+mikrotik,ltap-2hnd|\
 mikrotik,routerboard-m11g)
 	ucidef_set_rssimon "wlan0" "200000" "1"
 	ucidef_set_led_rssi "rssilow" "RSSILOW" "green:rssi0" "wlan0" "1" "100"

target/linux/ramips/mt7621/base-files/etc/board.d/02_network

@@ -12,6 +12,7 @@ ramips_setup_interfaces()
 	asus,rp-ac56|\
 	asus,rp-ac87|\
 	edimax,re23s|\
+	mikrotik,ltap-2hnd|\
 	mikrotik,routerboard-m11g|\
 	netgear,ex6150|\
 	sercomm,na502|\
@@ -218,6 +219,9 @@ ramips_setup_macs()
 		lan_mac=$(mtd_get_mac_ascii Config lan_hwaddr)
 		wan_mac=$(mtd_get_mac_ascii Config wan_hwaddr)
 		label_mac=$lan_mac
+	mikrotik,ltap-2hnd)
+		label_mac=$(cat "/sys/firmware/mikrotik/hard_config/mac_base")
+		lan_mac=$label_mac
 		;;
 	tplink,mr600-v2-eu)
 		label_mac=$(cat "/sys/class/net/eth0/address")