[media] V4L: sh-mobile-ceu-camera: fix mixed CSI2 & parallel camera case

The current sh_mobile_ceu_camera driver can cause an Oops, if a CSI2 and a
parallel camera are registered on the same CEU. Fix it by making CSI2
association with a camera more targeted.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>