ramips: add support for GL-inet GL-MT300N-V2

This patch adds supports for the GL-inet GL-MT300N-V2.

Specification:
- SoC: MediaTek MT7628AN
- Flash: 16 MiB (W25Q128FVSG)
- RAM: 128 MiB DDR
- Ethernet: 1 x WAN (100 Mbps) and 1 x LAN (100 Mbps)
- USB: 1 x USB 2.0 port
- Button: 1 x switch button, 1 x reset button
- LED: 3 x LEDS (system power led is not GPIO controller)
- UART: 1 x UART on PCB (JP1: 3.3V, RX, TX, GND)

Installation through Luci:
- The original firmware is LEDE, so both LuCI or sysupgrade can be used.
- Do not keep settings, for sysupgrade please use the -n option.

Installation through bootloader webserver:
- Plug power and hold reset button until red LED blink to bright.
- Install sysupgrade image using web interface on 192.168.1.1.

Signed-off-by: Kyson Lok <kysonlok@gmail.com>
[match maximum image size with firmware partition]
Signed-off-by: Mathias Kresin <dev@kresin.me>

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

@@ -189,6 +189,9 @@ gl-mt300n|\
 gl-mt750)
 	set_wifi_led "$board:wlan"
 	;;
+gl-mt300n-v2)
+	set_wifi_led "$board:red:wlan"
+	;;
 hc5661|\
 hc5661a)
 	ucidef_set_led_default "system" "system" "$board:blue:system" "1"

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

@@ -180,6 +180,10 @@ ramips_setup_interfaces()
 		ucidef_add_switch "switch0" \
 			"1:lan" "2:lan" "3:lan" "4:lan" "0:wan" "6@eth0"
 		;;
+	gl-mt300n-v2)
+		ucidef_add_switch "switch0" \
+			"1:lan" "0:wan" "6@eth0"
+		;;
 	awapn2403)
 		ucidef_add_switch "switch0" \
 			"0:lan" "1:wan" "6@eth0"