media: visl: Fix ERANGE error when setting enum controls

The visl driver supports both frame and slice mode, with and without a
start-code. But, the range and default for these enum controls was not
set, which currently limits the decoder to enums with a value of 0. Fix
this by setting the decoder mode and start code controls for both the
H.264 and HEVC codecs.

Fixes: 0c078e31 ("media: visl: add virtual stateless decoder driver")
Cc: stable@vger.kernel.org
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Sebastian Fricke <sebastian.fricke@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>