usb: gadget: udc: renesas_usb3: fix device leak at unbind

Make sure to drop the reference to the companion device taken during
probe when the driver is unbound.

Fixes: 39facfa ("usb: gadget: udc: renesas_usb3: Add register of usb role switch")
Cc: stable@vger.kernel.org	# 4.19
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20250724091910.21092-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: jhovold

drivers/usb/gadget/udc/renesas_usb3.c

@@ -2657,6 +2657,7 @@ static void renesas_usb3_remove(struct platform_device *pdev)
 	struct renesas_usb3 *usb3 = platform_get_drvdata(pdev);
 
 	debugfs_remove_recursive(usb3->dentry);
+	put_device(usb3->host_dev);
 	device_remove_file(&pdev->dev, &dev_attr_role);
 
 	cancel_work_sync(&usb3->role_work);