ramips: add support for D-Link DAP-X1860 A1

The DAP-X1860 is a wall-plug AX1800 repeater.

Specifications:
- MT7621, 256 MiB RAM, 128 MiB SPI NAND
- MT7915 + MT7975 2x2 802.11ax (DBDC)
- Ethernet: 1 port 10/100/1000
- LED RSSI bargraph (2x green, 1x red/orange), status
  and RSSI LEDs are incorrectly populated red/orange
  (should be red/green according to documentation)

Installation:
- Keep reset button pressed during plug-in
- Web Recovery Updater is at 192.168.0.50
- Upload factory.bin, confirm flashing
  (seems to work best with Chromium-based browsers)

Revert to OEM firmware:
- tar -xvf DAP-X1860_RevA_Firmware_101b94.bin
- openssl enc -d -md md5 -aes-256-cbc -in FWImage.st2 \
  -out FWImage.st1 -k MB0dBx62oXJXDvt12lETWQ==
- tar -xvf FWImage.st1
- flash kernel_DAP-X1860.bin via Recovery

Signed-off-by: Sebastian Schaper <openwrt@sebastianschaper.net>

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

@@ -56,6 +56,13 @@ jcg,y2|\
 xzwifi,creativebox-v1)
 	ucidef_set_led_netdev "internet" "internet" "blue:internet" "wan"
 	;;
+dlink,dap-x1860-a1)
+	ucidef_set_rssimon "wlan1" "200000" "1"
+	ucidef_set_led_rssi "rssilow" "RSSILOW" "orange:rssilow" "wlan1" "1" "25"
+	ucidef_set_led_rssi "rssimediumlow" "RSSIMEDIUMLOW" "green:rssilow" "wlan1" "26" "100"
+	ucidef_set_led_rssi "rssimediumhigh" "RSSIMEDIUMHIGH" "green:rssimedium" "wlan1" "51" "100"
+	ucidef_set_led_rssi "rssihigh" "RSSIHIGH" "green:rssihigh" "wlan1" "76" "100"
+	;;
 dlink,dir-1960-a1|\
 dlink,dir-2640-a1|\
 dlink,dir-2660-a1)

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

@@ -11,6 +11,7 @@ ramips_setup_interfaces()
 	ampedwireless,ally-00x19k|\
 	asus,rp-ac56|\
 	asus,rp-ac87|\
+	dlink,dap-x1860-a1|\
 	edimax,re23s|\
 	mikrotik,ltap-2hnd|\
 	mikrotik,routerboard-m11g|\

target/linux/ramips/mt7621/base-files/etc/hotplug.d/ieee80211/10_fix_wifi_mac

@@ -22,6 +22,13 @@ case "$board" in
 		hw_mac_addr="$(mtd_get_mac_binary factory 0x4)"
 		macaddr_add $hw_mac_addr "$PHYNBR" > /sys${DEVPATH}/macaddress
 		;;
+	dlink,dap-x1860-a1)
+		hw_mac_addr="$(mtd_get_mac_binary factory 0x4)"
+		[ "$PHYNBR" = "0" ] && \
+			macaddr_add $hw_mac_addr 1 > /sys${DEVPATH}/macaddress
+		[ "$PHYNBR" = "1" ] && \
+			macaddr_add $hw_mac_addr 4 > /sys${DEVPATH}/macaddress
+		;;
 	dlink,dir-853-a3)
 		[ "$PHYNBR" = "0" ] && \
 			macaddr_setbit_la "$(mtd_get_mac_binary factory 0xe000)" \