ARM: davinci: DA850: Add GPIO pinmux configuration for wl1271

The wl1271 daughter board makes use of a few GPIOs:
GPIO6_9 is used for powering down/up the WLAN functionality.
GPIO6_10 is used as an input IRQ line from the WLAN chip.

Add the required pinmux configuration for these GPIOs.

Signed-off-by: Ido Yariv <ido@wizery.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>