riscv: dts: microchip: update memory configuration for v2022.10

In the v2022.10 reference design, the seg registers are going to be
changed, resulting in a required change to the memory map in Linux.
A small 4M reservation is made at the end of 32-bit DDR to provide some
memory for the HSS to use, so that it can cache its payload.bin between
reboots of a specific context.
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>

arch/riscv/boot/dts/microchip/mpfs-icicle-kit.dts

@@ -33,15 +33,26 @@ cpus {
 
 	ddrc_cache_lo: memory@80000000 {
 		device_type = "memory";
-		reg = <0x0 0x80000000 0x0 0x2e000000>;
+		reg = <0x0 0x80000000 0x0 0x40000000>;
 		status = "okay";
 	};
 
 	ddrc_cache_hi: memory@1000000000 {
 		device_type = "memory";
-		reg = <0x10 0x0 0x0 0x40000000>;
+		reg = <0x10 0x40000000 0x0 0x40000000>;
 		status = "okay";
 	};
+
+	reserved-memory {
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		hss_payload: region@BFC00000 {
+			reg = <0x0 0xBFC00000 0x0 0x400000>;
+			no-map;
+		};
+	};
 };
 
 &core_pwm0 {