v4l2_stateful_decoder: Increase queue size

Increase the queue size by 1 in the v4l2_stateful_decoder. The current
queue size of 8 is incapable of handling VP9 superframes on certain
platforms.

BUG=b:280053586
TEST=Ran video.PlatformDecoding.v4l2_stateful_vp9_0_group1_buf on hana.

Change-Id: I08598c78649844f60e63792fc394e38bb5ba5bf1
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/drm-tests/+/4977197
Commit-Queue: Justin Green <greenjustin@google.com>
Tested-by: Justin Green <greenjustin@google.com>
Reviewed-by: Fritz Koenig <frkoenig@chromium.org>
1 file changed