ar71xx: wndr4300: enable 5V power for the USB port

The 5V power of the USB is controlled by a GPIO pin of
the external WiFi chip. Setup the GPIO bitmasks in the
platform data of the WiFi chip to ensure that the 5V
power gets enabled by the ath9k driver.

Based on the the WNDR3700v4 support patch from Ralph Perlich:
  http://patchwork.openwrt.org/patch/4763/

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@40478 3c298f89-4303-0410-b956-a3cf2f4a3e73
ar71xx: wndr4300: indicate WNDR3700v4 in the kernel support files

Apart from the wireless chip, the WNDR3700 v4 and the WNDR4300
is the same device. Indicate this in the kernel files.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@40479 3c298f89-4303-0410-b956-a3cf2f4a3e73