[media] soc-camera: Support user-configurable line stride

Add a capabilities field to the soc_camera_host structure to flag hosts
that support user-configurable line strides. soc_camera_try_fmt() then
passes the user-provided bytesperline and sizeimage format fields to
such hosts, and expects the host to check (and fix if needed) the
values.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
[g.liakhovetski@gmx.de: fix a typo in mx2_camera.c]
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>