media: mc: entity: Move media_entity_get_fwnode_pad() out of graph walk section

The media_entity_get_fwnode_pad() function is unrelated to the graph
traversal code that it is currently bundled with. Move it with the
media_entity_remote_pad() function.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>