ramips: add support for TP-Link RE500 v1

This device uses the same hardware as RE650 v1 which got supported in
8c51dde.

Hardware specification:

- SoC 880 MHz - MediaTek MT7621AT
- 128 MB of DDR3 RAM
- 16 MB - Winbond 25Q128FVSG
- 4T4R 2.4 GHz - MediaTek MT7615E
- 4T4R 5 GHz - MediaTek MT7615E
- 1x 1 Gbps Ethernet - MT7621AT integrated
- 7x LEDs (Power, 2G, 5G, WPS(x2), Lan(x2))
- 4x buttons (Reset, Power, WPS, LED)
- UART header (J1) - 2:GND, 3:RX, 4:TX
  Serial console @ 57600,8n1

Flash instructions:

Upload
openwrt-ramips-mt7621-tplink_re500-v1-squashfs-factory.bin
from the RE500 web interface.

TFTP recovery to stock firmware:

Unfortunately, I can't find an easy way to recover the RE
without opening the device and using modified binaries. The
TFTP upload will only work if selected from u-boot, which
means you have to open the device and attach to the serial
console. The TFTP update procedure does *not* accept the
published vendor firmware binaries. However, it allows to
flash kernel + rootfs binaries, and this works if you have
a backup of the original contents of the flash. It's probably
possible to create special image out of the vendor binaries
and use that as recovery image.

Signed-off-by: Christoph Krapp <achterin@googlemail.com>
[remove dts-v1 in DTSI, do not touch WiFi LEDs for RE650, keep
state_default in DTS files, fix label-mac-device, use lower case
for WiFi LEDs]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

tools/firmware-utils/src/tplink-safeloader.c

@@ -1858,6 +1858,43 @@ static struct device_info boards[] = {
 		.last_sysupgrade_partition = "file-system"
 	},
 
+	/** Firmware layout for the RE500 */
+	{
+		.id     = "RE500-V1",
+		.vendor = "",
+		.support_list =
+			"SupportList:\r\n"
+			"{product_name:RE500,product_ver:1.0.0,special_id:00000000}\r\n"
+			"{product_name:RE500,product_ver:1.0.0,special_id:55530000}\r\n"
+			"{product_name:RE500,product_ver:1.0.0,special_id:45550000}\r\n"
+			"{product_name:RE500,product_ver:1.0.0,special_id:4A500000}\r\n"
+			"{product_name:RE500,product_ver:1.0.0,special_id:43410000}\r\n"
+			"{product_name:RE500,product_ver:1.0.0,special_id:41550000}\r\n"
+			"{product_name:RE500,product_ver:1.0.0,special_id:41530000}\r\n",
+		.support_trail = '\x00',
+		.soft_ver = NULL,
+
+		/* We're using a dynamic kernel/rootfs split here */
+		.partitions = {
+			{"fs-uboot", 0x00000, 0x20000},
+			{"firmware", 0x20000, 0xde0000},
+			{"partition-table", 0xe00000, 0x02000},
+			{"default-mac", 0xe10000, 0x00020},
+			{"pin", 0xe10100, 0x00020},
+			{"product-info", 0xe11100, 0x01000},
+			{"soft-version", 0xe20000, 0x01000},
+			{"support-list", 0xe21000, 0x01000},
+			{"profile", 0xe22000, 0x08000},
+			{"user-config", 0xe30000, 0x10000},
+			{"default-config", 0xe40000, 0x10000},
+			{"radio", 0xff0000, 0x10000},
+			{NULL, 0, 0}
+		},
+
+		.first_sysupgrade_partition = "os-image",
+		.last_sysupgrade_partition = "file-system"
+	},
+
 	/** Firmware layout for the RE650 */
 	{
 		.id     = "RE650-V1",