ipq807x: add Arcadyan AW1000 support

ipq807x: add Arcadyan AW1000 support

Hardware specification:
  SoC: Qualcomm IPQ8072A
  Flash: Toshiba NAND 1GiB
  RAM: 1 GiB of DDR3 466 MHz
  Ethernet: 4x 1Gbps + 1x 2.5Gbps
  WiFi1: QCN5024 2.4GHz ax 4x4
  WiFi2: QCN5054 5GHz ax 4x4
  Button: WiFi, WPS, Reset
  Modem: RG500Q-EA
  USB: 1 x USB 3.0
  Power: DC 12V 4A

Flash instructions:
  1. Download the initramfs image, rename it to
     initramfs.bin, and host it with tftp server.
  2. Interrupt U-Boot and run these commands:
     tftpboot initramfs.bin
     bootm
  3. After openwrt boots up, use scp or luci web
     to upload sysupgrade.bin to upgrade.

Signed-off-by: Chukun Pan <amadeus@jmu.edu.cn>
Reviewed-by: Robert Marko <robimarko@gmail.com>