media: imx-mipi-csis: Remove an incorrect fwnode_handle_put() call
The commit in Fixes has removed an fwnode_graph_get_endpoint_by_id() call
in mipi_csis_subdev_init().
So the reference that was taken should not be released anymore in the
error handling path of the probe and in the remove function.
Remove the now incorrect fwnode_handle_put() calls.