usb: musb: omap2430: fix device leak at unbind

usb: musb: omap2430: fix device leak at unbind

Make sure to drop the reference to the control device taken by
of_find_device_by_node() during probe when the driver is unbound.

Fixes: 8934d3e4d0e7 ("usb: musb: omap2430: Don't use omap_get_control_dev()")
Cc: stable@vger.kernel.org	# 3.13
Cc: Roger Quadros <rogerq@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20250724091910.21092-5-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>