media: i2c: imx214: Use __free(fwnode_handle)

Use the __free(fwnode_handle) hook to free the endpoint when the
function exits to simplify the error path.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: André Apitzsch <git@apitzsch.eu>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>