msm: vidc: Support ioctl VIDIOC_ENUM_FRAMESIZES

Changed ioctl VIDIOC_ENUM_FRAMESIZES behavior in conformance with
V4L2 specification to be able to query based on pixel format.

Change-Id: Ia5803341070d14335cbb939108575f835471a857
Signed-off-by: Akshay Chandrashekhar Kalghatgi <akalghat@codeaurora.org>