Let v4l2_fwnode_endpoint_alloc_parse to figure out the type of the data
bus. As the old bindings did not require the "bus-type" property, we need
to rely on guessing between CSI-2 D-PHY and CCP2. Setting the type to
CSI-2 D-PHY will parse just that and succeed even if no data-lanes are
set.

Also add a comment on the matter to the driver to avoid breaking this in
the future.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>