[media] s5p-mfc: fix V4L2_CID_MIN_BUFFERS_FOR_CAPTURE on resolution change

G_CTRL on V4L2_CID_MIN_BUFFERS_FOR_CAPTURE will fail if userspace happens to
query it after getting a resolution change event and before the codec has
a chance to parse the header and switch to an initialized state.

Signed-off-by: Pawel Osciak <posciak@chromium.org>
Signed-off-by: Kiran AVND <avnd.kiran@samsung.com>
Signed-off-by: Arun Kumar K <arun.kk@samsung.com>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>