usb: musb: sunxi: Explicitly release USB PHY on exit

This fixes a kernel oops when unloading the driver due to usb_put_phy
being called after usb_phy_generic_unregister when the device is
detached. Calling usb_phy_generic_unregister causes x->dev->driver to
be NULL in usb_put_phy and results in a NULL pointer dereference.

Cc: [e-mail] # v4.3+
Signed-off-by: Jonathan Liu <[e-mail]>
Signed-off-by: Bin Liu <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/musb/sunxi.c

···
 	if (test_bit(SUNXI_MUSB_FL_HAS_SRAM, &glue->flags))
 		sunxi_sram_release(musb->controller->parent);
 
+	devm_usb_put_phy(glue->dev, glue->xceiv);
+
 	return 0;
 }