[media] s5p-mfc: Set vfl_dir for encoder

The vfl_dir flag is presently set to VFL_DIR_M2M only for decoder.
The encoder is not working because of this. So adding this flag
to the encoder part also.

Signed-off-by: Arun Kumar K <arun.kk@samsung.com>
Acked-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>