radeon/uvd: fix a h265 context size bug
Fixes a h265 video corruption bug which caused by uvd fw interface changes. Signed-off-by:sonjiang <sonny.jiang@amd.com> Cc: "12.0" <mesa-stable@lists.freedesktop.org> Reviewed-by:
Alex Deucher <alexander.deucher@amd.com> Reviewed-by:
Christian König <christian.koenig@amd.com> (cherry picked from commit b928ff6f)