media: v4l: fwnode: Use a less clash-prone name for MAX_DATA_LANES macro

Avoid using a generic name such as MAX_DATA_LANES in a header file widely
included in drivers. Instead, call it V4L2_FWNODE_CSI2_MAX_DATA_LANES.

Fixes: 4ee23621 ("media: v4l2-fwnode: suppress a warning at OF parsing logic")

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>