usb: phy: rename usb_nop_xceiv to usb_phy_generic

no functional changes, just renaming the function
in order to make it slightly clearer what it should
be used for, also matching the driver name.

Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/phy/phy-keystone.c

@@ -35,7 +35,7 @@
 #define PHY_REF_SSP_EN			BIT(29)
 
 struct keystone_usbphy {
-	struct usb_phy_gen_xceiv	usb_phy_gen;
+	struct usb_phy_generic	usb_phy_gen;
 	void __iomem			*phy_ctrl;
 };