usb: dwc3: imx8mp: fix device leak at unbind

[ Upstream commit 086a0e51 ]

Make sure to drop the reference to the dwc3 device taken by
of_find_device_by_node() on probe errors and on driver unbind.

Fixes: 6dd25659 ("usb: dwc3: add imx8mp dwc3 glue layer driver")
Cc: stable@vger.kernel.org	# 5.12
Cc: Li Jun <jun.li@nxp.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20250724091910.21092-2-johan@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>