media: ov5640: Add support for flash and lens devices

Parse async sub-devices related to the sensor by switching the async
sub-device registration function.

Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>