smdk4412-common: camera: fix EXIF attributes for S5C73M3 sensor

S5C73M3 sensor which is the back camera, doesn't return the EXIF
attributes using V4L2 IOCTL. This sensor interleaves YUV and JPEG
frames along with Metadata which contains the EXIF information.

This patch does the following:
Manually extract the EXIF information from the interleaved metadata
and implement ISO, Flash, Exposure, Exposure Time and Exposure Bias
EXIF attributes for S5C73M3.
Fix incorrect Exposure EXIF attribute that was reporting as 1'.

Change-Id: Id9faa64af498645099cccc9cbf28f2dbdfecd254