msm: msm8916: camera: Add parse gpio-vana property

The vana power supply is controlled by GPIO, parse
gpio-vana function is needed to support this
function. So add gpio-vana parse function in init
camera gpio table.

Change-Id: I065a423602a9b35c7e64e981b562744c3eb7e1ad
Signed-off-by: Wei Ding <weiding@codeaurora.org>