ARM: dts: sun4i: protab2: Remove stale pinctrl-names entry

Some nodes still have pinctrl-names entry, yet they don't have any pinctrl
group anymore. Drop them.
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>

arch/arm/boot/dts/sun4i-a10-pov-protab2-ips9.dts

@@ -197,7 +197,6 @@ &usb_otg {
 };
 
 &usbphy {
-	pinctrl-names = "default";
 	usb0_id_det-gpios = <&pio 7 4 (GPIO_ACTIVE_HIGH | GPIO_PULL_UP)>; /* PH4 */
 	usb0_vbus_det-gpios = <&pio 7 5 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)>; /* PH5 */
 	usb0_vbus-supply = <&reg_usb0_vbus>;