MIPS: dts: loongson: Add ISA node

ISA node is required by Loongson64 platforms to initialize
PIO support.

Kernel will hang at boot without ISA node.

Cc: stable@vger.kernel.org
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/boot/dts/loongson/loongson64-2k1000.dtsi

@@ -44,6 +44,13 @@ package0: bus@10000000 {
 			0 0x40000000 0 0x40000000 0 0x40000000
 			0xfe 0x00000000 0xfe 0x00000000 0 0x40000000>;
 
+		isa@18000000 {
+			compatible = "isa";
+			#size-cells = <1>;
+			#address-cells = <2>;
+			ranges = <1 0x0 0x0 0x18000000 0x4000>;
+		};
+
 		pm: reset-controller@1fe07000 {
 			compatible = "loongson,ls2k-pm";
 			reg = <0 0x1fe07000 0 0x422>;