ath79: add support for TP-Link RE350K v1

TP-Link RE350K v1 (FCC ID: TE7RE350K) is a wall-plug AC1200 Wi-Fi range
extender with 'Kasa Smart' support. Device is based on Qualcomm/Atheros
QCA9558 + QCA9882 + AR8035 platform and is available only on US market.

Specification:

- 720/600/200 MHz (CPU/DDR/AHB)
- 128 MB of RAM (DDR2)
- 16 MB of flash (SPI NOR)
- 1x 1 Gbps Ethernet (AR8035)
- 2T2R 2.4 GHz (QCA9558), with ext. PA (SE2565T) and LNA (SKY65971-11)
- 2T2R 5 GHz (QCA9882), with ext. PA (SE5003L1-R) and LNA (SKY65981-11)
- 2x U.FL connector on PCB
- 2x dual-band PCB antennas
- 1x LED, 2x dual-color LED (all driven by GPIO)
- 3x button (app config, led, reset)
- 1x mechanical on/off slide switch
- 1x UART (4-pin, 2.54 mm pitch) header on PCB
- 1x JTAG (8-pin, 1.27 mm pitch) header on PCB

Flash instruction:
Use 'factory' image directly in vendor GUI (default IP: 192.168.0.254,
default credentials: admin/admin).

Warning:
This device does not include any kind of recovery mechanism in U-Boot.

Vendor firmware access:
You can access vendor firmware over serial (RX line requires jumper
resistor in R306 place, near XTAL) with: root/sohoadmin credentials.

Signed-off-by: Piotr Dymacz <pepe2k@gmail.com>

target/linux/ath79/image/generic-tp-link.mk

@@ -109,6 +109,22 @@ define Device/tplink_archer-c7-v5
 endef
 TARGET_DEVICES += tplink_archer-c7-v5
 
+define Device/tplink_re350k-v1
+  $(Device/tplink)
+  ATH_SOC := qca9558
+  IMAGE_SIZE := 13760k
+  DEVICE_TITLE := TP-Link RE350K v1
+  DEVICE_PACKAGES := kmod-ath10k-ct ath10k-firmware-qca988x-ct
+  TPLINK_BOARD_ID := RE350K-V1
+  TPLINK_HWID := 0x0
+  TPLINK_HWREV := 0
+  KERNEL := kernel-bin | append-dtb | lzma | tplink-v1-header -O
+  IMAGE/sysupgrade.bin := append-rootfs | tplink-safeloader sysupgrade | \
+    check-size $$$$(IMAGE_SIZE) | append-metadata
+  IMAGE/factory.bin := append-rootfs | tplink-safeloader factory
+endef
+TARGET_DEVICES += tplink_re350k-v1
+
 define Device/tplink_re450-v2
   $(Device/tplink)
   ATH_SOC := qca9563