ath79: add support for D-Link DAP-1330/DAP-1365 A1

ath79: add support for D-Link DAP-1330/DAP-1365 A1

Port device support for DAP-1330 from the ar71xx target to ath79.

Additionally, images are generated for the European through-socket
case variant DAP-1365. Both devices run the same vendor firmware, the
only difference being the DAP_SIGNATURE field in the factory header.
The vendor's Web UI will display a model string stored in the flash.

Specifications:

 * QCA9533, 8 MiB Flash, 64 MiB RAM
 * One Ethernet Port (10/100)
 * Wall-plug style case (DAP-1365 with additional socket)
 * LED bargraph RSSI indicator

Installation:

 * Web UI: http://192.168.0.50 (or different address obtained via DHCP)
   There is no password set by default
 * Recovery Web UI: Keep reset button pressed during power-on
   until LED starts flashing red, upgrade via http://192.168.0.50
 * Some modern browsers may have problems flashing via the Web UI,
   if this occurs consider booting to recovery mode and flashing via:
   curl -F \
     files=@openwrt-ath79-generic-dlink_dap-1330-a1-squashfs-factory.bin \
     http://192.168.0.50/cgi/index

The device will use the same MAC address for both wired and wireless
interfaces, however it is stored at two different locations in the flash.

Signed-off-by: Sebastian Schaper <openwrt@sebastianschaper.net>