[media] m5mols: Fix set_fmt to return proper pixel format code

In case pixel format is modified in set_fmt by the driver,
the changes are not propagated back to the caller. Fix this
by adjusting passed  data for TRY and ACTIVE format.

Also remove redundant pixel format code information from
struct m5mols_info, it's already available in 'ffmt' array.
Remove pad number validation in set/get_fmt, this is already
done in the core.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: HeungJun Kim <riverful.kim@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>