[media] s5p-mfc: Move INIT_BUFFER_OPTIONS from v7 to v6

The register S5P_FIMV_D_INIT_BUFFER_OPTIONS holds good for v6
firmware too. So moving the definition from v7 regs to v6.

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 <m.chehab@samsung.com>