media: staging: rkisp1: don't lock media's graph_mutex when calling rkisp1_create_links

The function rkisp1_create_links calls media_entity_get_fwnode_pad
and media_create_pad_link in the mc api. Those calls don't require
locking the graph_mutex so remove the locking.

Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Acked-by: Helen Koike <helen.koike@collabora.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>