media: imx: imx7-media-csi: Set RFF burst type in imx7_csi_configure()

The RFF burst type is set in imx7_csi_dmareq_rff_enable(), which doesn't
match the function name. Move it to imx7_csi_configure().

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>