[media] vivid: use TPG_MAX_PLANES instead of hardcoding plane-arrays

Two arrays of size 'max number of planes' have a hardcoded size instead
of using TPG_MAX_PLANES. Fix that, since TPG_MAX_PLANES will be increased
later on.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>