ARC: HAPS: add HIGHMEM memory zone to DTS

This is required as a preparation of merging nSIM and HASP
defonfig and device tree.

As we have HIGHMEM disabled in both HAPS and nSIM defconfigs
this doesn't lead to any functional change.
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/boot/dts/haps_hs.dts

@@ -9,13 +9,15 @@
 / {
 	model = "snps,zebu_hs";
 	compatible = "snps,zebu_hs";
-	#address-cells = <1>;
-	#size-cells = <1>;
+	#address-cells = <2>;
+	#size-cells = <2>;
 	interrupt-parent = <&core_intc>;
 
 	memory {
 		device_type = "memory";
-		reg = <0x80000000 0x20000000>;	/* 512 */
+		/* CONFIG_LINUX_RAM_BASE needs to match low mem start */
+		reg = <0x0 0x80000000 0x0 0x20000000	/* 512 MB low mem */
+		       0x1 0x00000000 0x0 0x40000000>;	/* 1 GB highmem */
 	};
 
 	chosen {
@@ -31,8 +33,9 @@ fpga {
 		#address-cells = <1>;
 		#size-cells = <1>;
 
-		/* child and parent address space 1:1 mapped */
-		ranges;
+		/* only perip space at end of low mem accessible
+			  bus addr,  parent bus addr, size    */
+		ranges = <0x80000000 0x0 0x80000000 0x80000000>;
 
 		core_clk: core_clk {
 			#clock-cells = <0>;