arm64: dts: add .dts for GICv3 Foundation model

The ARMv8 Foundation model sports a command line parameter to use
a GICv3 emulation instead of the default GICv2 interrupt controller.
Add a new .dts file which reuses most of the definitions of the
existing model while just adding the required properties for the
GICv3 node.

This allows the public Foundation model to run with a GICv3.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

arch/arm64/boot/dts/arm/Makefile

-dtb-$(CONFIG_ARCH_VEXPRESS) += foundation-v8.dtb
+dtb-$(CONFIG_ARCH_VEXPRESS) += foundation-v8.dtb foundation-v8-gicv3.dtb
 dtb-$(CONFIG_ARCH_VEXPRESS) += juno.dtb juno-r1.dtb
 dtb-$(CONFIG_ARCH_VEXPRESS) += rtsm_ve-aemv8a.dtb
 dtb-$(CONFIG_ARCH_VEXPRESS) += vexpress-v2f-1xv7-ca53x2.dtb

arch/arm64/boot/dts/arm/foundation-v8-gicv3.dts

+/*
+ * ARM Ltd.
+ *
+ * ARMv8 Foundation model DTS (GICv3 configuration)
+ */
+
+#include "foundation-v8.dtsi"
+
+/ {
+	gic: interrupt-controller@2f000000 {
+		compatible = "arm,gic-v3";
+		#interrupt-cells = <3>;
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+		interrupt-controller;
+		reg =	<0x0 0x2f000000 0x0 0x10000>,
+			<0x0 0x2f100000 0x0 0x200000>,
+			<0x0 0x2c000000 0x0 0x2000>,
+			<0x0 0x2c010000 0x0 0x2000>,
+			<0x0 0x2c02f000 0x0 0x2000>;
+		interrupts = <1 9 4>;
+
+		its: its@2f020000 {
+			compatible = "arm,gic-v3-its";
+			msi-controller;
+			reg = <0x0 0x2f020000 0x0 0x20000>;
+		};
+	};
+};