msm: vidc: Use v4l2 format structure to store properties

Currently different structures are used to store width,
height, codec, buffer sizes and counts. All this can be
instead stored in v4l2 format structure inside the
instance. By doing this get/set format also becomes very
simple. It is just updating the sizes and copying the v4l2
format structure.

Change-Id: Iab011e9a8f50b17ffec84c2f18a4977bf973a6b9
Signed-off-by: Vaibhav Deshu Venkatesh <vdeshuve@codeaurora.org>