msm: vidc: Fix downscaling check for HEIC

Don't check for downscaling when format is HEIC. Downscaling is not
required for HEIC even if it may have non-matching
input/output resolution.

CRs-Fixed: 2251048

Change-Id: I7c243ebc3d5d1fd39e9ec4138309cd7acc5e989d
Signed-off-by: Amit Shekhar <ashekhar@codeaurora.org>