msm: vidc: Correct resolution check

Compare the number of macroblock per frame instead of
the number of pixels per frame to avoid batching enabled
for video playback resolutions greater than 1080p.

Change-Id: I07bbfae5513e9dc4b57058edea587d315d3f0c21
Signed-off-by: Maheshwar Ajja <majja@codeaurora.org>