ARM: dts: dra7: add labels to DWC3 nodes

by adding labels to DWC3 nodes, it's far easier
for boards to reference them.
Signed-off-by: Felipe Balbi <balbi@ti.com>
[tony@atomide.com: updated for otg 4 move to dra74x.dtsi]
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/dra7.dtsi

@@ -1219,7 +1219,7 @@ usb3_phy1: phy@4a084400 {
 			};
 		};
 
-		omap_dwc3_1@48880000 {
+		omap_dwc3_1: omap_dwc3_1@48880000 {
 			compatible = "ti,dwc3";
 			ti,hwmods = "usb_otg_ss1";
 			reg = <0x48880000 0x10000>;
@@ -1240,7 +1240,7 @@ usb1: usb@48890000 {
 			};
 		};
 
-		omap_dwc3_2@488c0000 {
+		omap_dwc3_2: omap_dwc3_2@488c0000 {
 			compatible = "ti,dwc3";
 			ti,hwmods = "usb_otg_ss2";
 			reg = <0x488c0000 0x10000>;
@@ -1262,7 +1262,7 @@ usb2: usb@488d0000 {
 		};
 
 		/* IRQ for DWC3_3 and DWC3_4 need IRQ crossbar */
-		omap_dwc3_3@48900000 {
+		omap_dwc3_3: omap_dwc3_3@48900000 {
 			compatible = "ti,dwc3";
 			ti,hwmods = "usb_otg_ss3";
 			reg = <0x48900000 0x10000>;

arch/arm/boot/dts/dra74x.dtsi

@@ -46,7 +46,7 @@ pmu {
 	};
 
 	ocp {
-		omap_dwc3_4@48940000 {
+		omap_dwc3_4: omap_dwc3_4@48940000 {
 			compatible = "ti,dwc3";
 			ti,hwmods = "usb_otg_ss4";
 			reg = <0x48940000 0x10000>;