msm:vidc: Reduce decoder input buffer size & count

Default input buffer size is calculated based on 4k.
For the targets that doesn't support 4k, calculate the
buffer size for the highest resolution it supported.

Input buffer count is defined considering HFR(240, 480,...)
usecase, but low spec targets like bengal max HFR is 120
and may not require high buffer count. Reduced the count
for low tier targets.

CRs-Fixed: 2617714
Change-Id: Ica78e5d3393a90f1d0ae2556cb14881451525ded
Signed-off-by: Manikanta Kanamarlapudi <kmanikan@codeaurora.org>