media: dt-bindings: Add bindings for Dongwoon DW9714 voice coil

Dongwoon DW9714 is a voice coil lens driver.

Also add a vendor prefix for Dongwoon for one did not exist previously.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>