arm64: dts: fvp: Add system timer for broadcast during CPU idle

Introduce a system-level timer node in the FVP device tree to act as
a broadcast timer when CPUs are in context losing idle states where
the local timer stops on entering such low power states.

This change complements recent CPU idle state additions.

Tested-by: Leo Yan <leo.yan@arm.com>
Message-Id: <20250509154640.836093-1-sudeep.holla@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

Author: sudeep-holla

arch/arm64/boot/dts/arm/fvp-base-revc.dts

@@ -217,6 +217,19 @@
 			     <GIC_PPI 10 IRQ_TYPE_LEVEL_LOW>;
 	};
 
+	timer@2a810000 {
+		compatible = "arm,armv7-timer-mem";
+		reg = <0x0 0x2a810000 0x0 0x10000>;
+		ranges = <0 0x0 0x2a820000 0x20000>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		frame@2a830000 {
+			frame-number = <1>;
+			interrupts = <GIC_SPI 26 IRQ_TYPE_LEVEL_HIGH>;
+			reg = <0x10000 0x10000>;
+		};
+	};
+
 	pmu {
 		compatible = "arm,armv8-pmuv3";
 		interrupts = <GIC_PPI 7 IRQ_TYPE_LEVEL_HIGH>;