msm: camera: Add front camera wled flash support

Front camera flash has WLED support for selfie flash.
This change enables WLED support for front image sensor to
request wled framework for brightness change based on request.

Change-Id: I84555dab7e2609814ac98448fbb3fb06da9ec7fc
Signed-off-by: Jigarkumar Zala <jzala@codeaurora.org>