media: imx: imx6-media-csi: Replace Y16 with Y10 and Y12

The driver doesn't really support V4L2_PIX_FMT_Y16, as there's no 16-bit
greyscale media bus code defined by the kernel. It (ab)uses the format
to capture 10-bit and 12-bit greyscale formats. Fix it to properly
support MEDIA_BUS_FMT_Y10_1X10 and MEDIA_BUS_FMT_Y12_1X12 instead.

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