ramips: add support for ELECOM WRC-1167GST2

ELECOM WRC-1167GST2 is a 2.4/5 GHz band 11ac (Wi-Fi 5) router, based
on MT7621A.

Specification:

- SoC		: MediaTek MT7621A
- RAM		: DDR3 256 MiB
- Flash		: SPI-NOR 32 MiB
- WLAN		: 2.4/5 GHz 2T2R (MediaTek MT7615D)
- Ethernet	: 10/100/1000 Mbps x5
  - Switch	: MediaTek MT7530 (SoC)
- LED/keys	: 6x/6x (2x buttons, 1x slide-switch)
- UART		: through-hole on PCB
  - J4: 3.3V, GND, TX, RX from ethernet port side
  - 57600n8
- Power		: 12VDC, 1A

MAC addresses:

LAN	: 04:AB:18:**:**:07 (Factory, 0xE000 (hex))
WAN	: 04:AB:18:**:**:08 (Factory, 0xE006 (hex))
2.4 GHz	: 04:AB:18:**:**:09 (none)
5 GHz	: 04:AB:18:**:**:0A (none)

Flash instruction using factory image:

1. Boot WRC-1167GST2 normally
2. Access to "http://192.168.2.1/" and open firmware update page
   ("ファームウェア更新")
3. Select the OpenWrt factory image and click apply ("適用") button
4. Wait ~150 seconds to complete flashing

Notes:

- there is no way to configure the correct MAC address for secondary phy
  (5GHz) on MT7615D
- Wi-Fi band on primary phy (2.4GHz) cannot be limitted by specifying
  ieee80211-freq-limit
  (fail to register secondary phy due to error)
- mtd-mac-address in the wifi node is required for using
  mtd-mac-address-increment

Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com>
[rebase onto split DTSI]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

target/linux/ramips/dts/mt7621_elecom_wrc-1167gst2.dts

@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "mt7621_elecom_wrc-gs-1pci.dtsi"
+
+/ {
+	compatible = "elecom,wrc-1167gst2", "mediatek,mt7621-soc";
+	model = "ELECOM WRC-1167GST2";
+};
+
+&gmac0 {
+	mtd-mac-address = <&factory 0xe000>;
+};
+
+&wan {
+	mtd-mac-address = <&factory 0xe006>;
+};
+
+&partitions {
+	partition@50000 {
+		compatible = "denx,uimage";
+		label = "firmware";
+		reg = <0x50000 0x1800000>;
+	};
+
+	partition@1850000 {
+		label = "tm_pattern";
+		reg = <0x1850000 0x400000>;
+		read-only;
+	};
+
+	partition@1c50000 {
+		label = "tm_key";
+		reg = <0x1c50000 0x100000>;
+		read-only;
+	};
+
+	partition@1d50000 {
+		label = "nvram";
+		reg = <0x1d50000 0xb0000>;
+		read-only;
+	};
+
+	partition@1e00000 {
+		label = "user_data";
+		reg = <0x1e00000 0x200000>;
+		read-only;
+	};
+};
+
+&wifi {
+	mtd-mac-address = <&factory 0xe006>;
+	mtd-mac-address-increment = <1>;
+};

target/linux/ramips/image/mt7621.mk

@@ -434,6 +434,14 @@ define Device/elecom_wrc-1167gs2-b
 endef
 TARGET_DEVICES += elecom_wrc-1167gs2-b
 
+define Device/elecom_wrc-1167gst2
+  $(Device/elecom_wrc-gs)
+  IMAGE_SIZE := 24576k
+  DEVICE_MODEL := WRC-1167GST2
+  ELECOM_HWNAME := WRC-1167GST2
+endef
+TARGET_DEVICES += elecom_wrc-1167gst2
+
 define Device/elecom_wrc-1750gs
   $(Device/elecom_wrc-gs)
   IMAGE_SIZE := 11264k