msm: vidc: Check width/height limits for downscaling

Function that does scaling related checks is not being
called currently. Also, made changes in logs to give more
information about failure.

CRs-Fixed: 2062059
Change-Id: Ibec66a9c6f814420c68deb850e03f289d1ca400f
Signed-off-by: Vaibhav Deshu Venkatesh <vdeshuve@codeaurora.org>