powerpc/microwatt: Add Ethernet to device tree

The liteeth network device is used in the Microwatt soc.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210826122653.3236867-2-joel@jms.id.au

arch/powerpc/boot/dts/microwatt.dts

@@ -127,6 +127,18 @@ UART0: serial@2000 {
 			fifo-size = <16>;
 			interrupts = <0x10 0x1>;
 		};
+
+		ethernet@8020000 {
+			compatible = "litex,liteeth";
+			reg = <0x8021000 0x100
+				0x8020800 0x100
+				0x8030000 0x2000>;
+			reg-names = "mac", "mido", "buffer";
+			litex,rx-slots = <2>;
+			litex,tx-slots = <2>;
+			litex,slot-size = <0x800>;
+			interrupts = <0x11 0x1>;
+		};
 	};
 
 	chosen {