The use of GPIOs should be optional for the generic phy, otherwise
the Altera SOCFPGA platform at least is broken.
Fixes breakage caused by a combination of 
e9f2cefb0cd "usb: phy:
generic: migrate to gpio_desc" and 
135b3c4304d "usb: dwc2: platform:
add generic PHY framework support".
Reviewed-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
                        clk_rate = 0;
 
                needs_vcc = of_property_read_bool(node, "vcc-supply");
-               nop->gpiod_reset = devm_gpiod_get(dev, "reset-gpios");
+               nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset-gpios");
                err = PTR_ERR(nop->gpiod_reset);
                if (!err) {
-                       nop->gpiod_vbus = devm_gpiod_get(dev,
+                       nop->gpiod_vbus = devm_gpiod_get_optional(dev,
                                                         "vbus-detect-gpio");
                        err = PTR_ERR(nop->gpiod_vbus);
                }