media/gpu/v4l2: fix VP8 decoder control

VP8 control ID is is set to [V4L2_CTRL_TYPE_VP8_FRAME_HEADER]
but should be [V4L2_CID_MPEG_VIDEO_VP8_FRAME_HEADER] instead.
The wrong control ID causes the VP8 decoder to fail.

BUG=965375
TEST=ran tast tests with video.DecodeAccelVP8 and
video_decode_accelerator_tests on veyron_minnie-kernelnext

Change-Id: Ia7da9ed513da07450fd96969461ac008245bfad8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1807637Reviewed-by: Alexandre Courbot <acourbot@chromium.org>
Commit-Queue: Alexandre Courbot <acourbot@chromium.org>
Cr-Commit-Position: refs/heads/master@{#697078}

media/gpu/v4l2/v4l2_vp8_accelerator.cc

@@ -222,7 +222,7 @@ bool V4L2VP8Accelerator::SubmitDecode(
 
   struct v4l2_ext_control ctrl;
   memset(&ctrl, 0, sizeof(ctrl));
-  ctrl.id = V4L2_CTRL_TYPE_VP8_FRAME_HEADER;
+  ctrl.id = V4L2_CID_MPEG_VIDEO_VP8_FRAME_HEADER;
   ctrl.size = sizeof(v4l2_frame_hdr);
   ctrl.ptr = &v4l2_frame_hdr;