media: chips-media: wave5: Fix gray color on screen

When a decoder instance is created, the W5_CMD_ERR_CONCEAL register
should be initialized to 0. Otherwise, gray color is occasionally
displayed on the screen while decoding.

Fixes: 45d1a2b9 ("media: chips-media: wave5: Add vpuapi layer")
Cc: stable@vger.kernel.org
Signed-off-by: Jackson.lee <jackson.lee@chipsnmedia.com>
Signed-off-by: Nas Chung <nas.chung@chipsnmedia.com>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Sebastian Fricke <sebastian.fricke@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>