add private_lib for NL80211 and wext driver.

Copied from hardware/broadcom/wlan/bcmdhd/wpa_supplicant_8_lib and modified
to work with generic wext driver.

Change-Id: Id33647ac6c8ae7faa9ed0b7cd24c59e0c76fdd85
Signed-off-by: Vishal Bhoj <vishal.bhoj@linaro.org>