phy: ti: omap-usb2: 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: 478b6c74 ("usb: phy: omap-usb2: 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/20250724131206.2211-3-johan@kernel.org


Signed-off-by: Vinod Koul <vkoul@kernel.org>