mips: dts: ralink: mt7628a: Harmonize EHCI/OHCI DT nodes name

In accordance with the Generic EHCI/OHCI bindings the corresponding node
name is suppose to comply with the Generic USB HCD DT schema, which
requires the USB nodes to have the name acceptable by the regexp:
"^usb(@.*)?" . Make sure the "generic-ehci" and "generic-ohci"-compatible
nodes are correctly named.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/boot/dts/ralink/mt7628a.dtsi

@@ -275,7 +275,7 @@ usb_phy: usb-phy@10120000 {
 		reset-names = "host", "device";
 	};
 
-	ehci@101c0000 {
+	usb@101c0000 {
 		compatible = "generic-ehci";
 		reg = <0x101c0000 0x1000>;