ath79: add support for Aruba AP-105

ath79: add support for Aruba AP-105

SoC: Atheros AR7161-8C1A @ 680 MHz
RAM: 128MB - 2x Etron Technology EM6AB160TSA-5G
NOR: 16MB - 1x MXIC MX25L12845EMI-10G (SPI-NOR)
WI1: Atheros AR9223-AC1A 802.11bgn
WI2: Atheros AR9220-AC1A 802.11an
ETH: Atheros AR8021-BL1E + PoE
LED: Dual-Color Power/Status, Ethernet, WLAN2G and WLAN5G
BTN: 1 x Reset
I2C: AT97SC4303s TPM (needs driver!)
CON: RS232-level 8P8C/RJ45 Console Port - 9600 Baud

Factory installation:

 - Needs a u-boot replacement. See Wiki for
   information on how to do a in-circut flash with
   a SPI-Flasher like a CH314A or flashrom. Wiki page
   can be found at https://openwrt.org/toh/aruba/aruba_ap-105

 - Be careful when dis- and reassembling the device to
   not squish any of the antenna cables in the process!

 - Be sure to make a full 16 MiB backup of your device
   before flashing the new u-boot! This is needed if you
   ever have interest in reverting back to stock firmware.

Not working:

 - TPM (needs a driver)

Signed-off-by: Chris Blake <chrisrblake93@gmail.com>