[media] s5p-mfc: remove meaningless memory bank assignment

This patch removes meaningless assignment of memory bank to itself.

Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Acked-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>