[media] m5mols: Remove mode_save field from struct m5mols_info

There is no need to keep this in the drivers' private data structure,
an on the stack variable is enough. Also simplify a bit the ISP state
switching function.

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