usb: phy-generic: fix nop xceiv probe

Commit bd27fa44 (usb: phy: generic:
Don't use regulator framework for RESET line) introduced regression: All
users of usb_nop_xceiv_register() will fail because there is no platform
data and the default reset GPIO is 0 which is a valid GPIO. Fix that.
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/phy/phy-generic.c

@@ -180,6 +180,8 @@ int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_gen_xceiv *nop,
 		clk_rate = pdata->clk_rate;
 		needs_vcc = pdata->needs_vcc;
 		nop->gpio_reset = pdata->gpio_reset;
+	} else {
+		nop->gpio_reset = -1;
 	}
 
 	nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),