ath79: qca9563: add support for Amplifi Router HD

ath79: qca9563: add support for Amplifi Router HD

Hardware:
    SoC: Qualcomm Atheros QCA956X ver 1 rev 0
    CPU clock: 775.000 MHz
    Memory: 128 MB DDR2
    Flash: 32 MB SPI NOR mx25l25635e
    Switch: Atheros AR8327 rev. 4
    Ethernet: 5x 10/100/1000 Mbps (1 WAN + 4 LAN)
    Buttons: 1x Reset
    Serial: TX, RX, GND, VCC
    Baudrate: 115200
    Wifi: Qualcomm Atheros qca988x 802.11ac/n - 3x3
          Qualcomm Atheros AR9561 802.11b/g/n - 3x3

Not working:
    Leds: 1x via a SPI controller
    Display: ST7789V or ILI9341V
    controlled by stm32f205.

Note:
    DSA changes are ready, but we have an issue with
    ports not working after 20-30 minutes. So for now
    we use swconfig.

Installation: serial connection only
There is a J11 four pin connector. You need to connect TX, RX and GND.
You can find very good information about the device here
https://github.com/alexanderhenne/AFi-R?tab=readme-ov-file#finding-j11

Upgrading via serial port:
1.  Download the kernel initramfs image. Copy the image to a TFTP server
2.  Connect to console on the AP, and connect the LAN1 port to your PC LAN
3.  Stop autoboot to get to U-boot shell
    Interrupt the autoboot process by pressing any key when prompted
4.  Transfer the kernel image with TFTP
    Set your ip address on your TFTP server to 192.168.1.254
    # tftpboot 0x81000000 amplifi-router-hd-initramfs-kernel.bin
5.  Load the image
    # bootm 0x81000000
6.  SCP sysupgrade image from your PC to the Amplifi HD
    (If you use a newer mac use scp -O)
    # scp openwrt-ath79-generic-ubnt_amplifi-router-hd-squashfs-sysupgrade.bin root@192.168.1.1:/tmp/
7.  Write sysupgrade to the firmware partition
    # mtd write /tmp/openwrt-ath79-generic-ubnt_amplifi-router-hd-squashfs-sysupgrade.bin firmware
8.  Reboot your device
    # reboot

Credit to alexanderhenne for all the information.

Signed-off-by: Kristian Skramstad <kristian+github@83.no>