Instead of forcing drivers to implement empty clock operations, make
them optional.
v4l2 clock registration in the soc-camera core should probably be
conditionned on the availability of those operations, but careful
review and/or testing of all drivers would be needed, so that should be
a separate step.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>