arm: dts: rockchip: remove usb-phy fallback string for rk3188

With the conversion of rockchip-usb-phy.yaml a long time used fallback
string for rk3066a/rk3188 was added. The linux driver doesn't do much with
the GRF phy address range, however the u-boot driver rockchip_usb2_phy.c
does. The bits in GRF_UOC0_CON2 for rk3066a/rk3188 and rk3288 for example
don't match. Remove the usb-phy fallback string for rk3188
to prevent possible strange side effects.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/dts/rk3188.dtsi b/arch/arm/dts/rk3188.dtsi
index 6764776..9a80f83 100644
--- a/arch/arm/dts/rk3188.dtsi
+++ b/arch/arm/dts/rk3188.dtsi
@@ -642,8 +642,7 @@
 	compatible = "rockchip,rk3188-grf", "syscon", "simple-mfd";
 
 	usbphy: usbphy {
-		compatible = "rockchip,rk3188-usb-phy",
-			     "rockchip,rk3288-usb-phy";
+		compatible = "rockchip,rk3188-usb-phy";
 		#address-cells = <1>;
 		#size-cells = <0>;
 		status = "disabled";