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-am335x.c

@@ -13,7 +13,7 @@
 #include "phy-generic.h"
 
 struct am335x_phy {
-	struct usb_phy_gen_xceiv usb_phy_gen;
+	struct usb_phy_generic usb_phy_gen;
 	struct phy_control *phy_ctrl;
 	int id;
 };