bcma: add comment to bcma_chipco_gpio_control
bcma: add comment to bcma_chipco_gpio_control

Add description to the function.

Signed-off-by: Hauke Mehrtens <435ddd46dc66c007a1fa20144c823d37e0d23436@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4588
Acked-by: Florian Fainelli <73262ad0334ab37227b2f7a0205f51db1e606681@openwrt.org>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs