media: cedrus: Make VP8 codec as capability

Commit 31d9b9ef8564 ("media: cedrus: Register all codecs as capability")
makes separate capability flags for each codec. However, VP8 codec was
merged at the same time as mentioned patch, so there is no capability
flag for it.

This patch adds capability flag for VP8 and enables it for all variants
except for V3s.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>