media: v4l2-ctrl: Add control for VP9 profile

Add a new control V4L2_CID_MPEG_VIDEO_VP9_PROFILE for VP9 profiles. This control
allows selecting the desired profile for VP9 encoder and querying for supported
profiles by VP9 encoder/decoder.

Though this control is similar to V4L2_CID_MPEG_VIDEO_VP8_PROFILE, we need to
separate this control from it because supported profiles usually differ between
VP8 and VP9.

Signed-off-by: Keiichi Watanabe <keiichiw@chromium.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>