[media] s5p-mfc: separate encoder parameters for h264 and mpeg4

This patch fixes a bug which caused overwriting h264 codec
parameters by mpeg4 parameters during V4L2 control setting.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>