usb: dwc3: pci: Use devm functions to get the phy GPIOs

Even though we only use them once, it is better to not put/release
the GPIOs immediately after use, so that others cannot claim them.

Use devm functions to get the phy GPIOs, so that they will be
automatically released when were unbound from the device and
remove the gpio_put calls.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>