media: pxa-camera: Match with device node, not the port node

V4L2 fwnode matching right now still works based on device nodes, not port
nodes. Fix this.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>