CHROMIUM: media: mediatek: vcodec: Enable HEVC main still picture

MTK devices that support HEVC also support main still picture profile,
but today, the main still picture profile is excluded.

This removes the skip mask for HEVC, which enables the main still
picture profile.

BUG=b:389168730
TEST=CTS HEIC decoding tests pass
UPSTREAM-TASK=b:390214569

Signed-off-by: Nathan Hebert <nhebert@chromium.org>
Change-Id: I848b0d898940cd12a7a35ac889830bef68f3351d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/6176726


Reviewed-by: Justin Green <greenjustin@google.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Commit-Queue: ChromeOS Auto Retry <chromeos-auto-retry@chromeos-bot.iam.gserviceaccount.com>
Signed-off-by: Hubert Mazur <hmazur@google.com>