media: imx: imx7-mipi-csis: Fix MEDIA_BUS_FMT_UYVY8_2X8 data alignment

The MEDIA_BUS_FMT_UYVY8_2X8 format reports a data alignment of 16 bits,
which isn't correct as it is output on an 8-bit bus. Fix it.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-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>