arm64: dts: imx8mm: adjust GIC CPU mask to match number of CPUs

i.MX 8M Mini has four Cortex-A CPUs, not six.  Using higher value is
harmless but adjust it to match real HW.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Jacky Bai <ping.bai@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mm.dtsi

@@ -194,16 +194,16 @@ psci {
 	pmu {
 		compatible = "arm,armv8-pmuv3";
 		interrupts = <GIC_PPI 7
-			     (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_HIGH)>;
+			     (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_HIGH)>;
 		interrupt-affinity = <&A53_0>, <&A53_1>, <&A53_2>, <&A53_3>;
 	};
 
 	timer {
 		compatible = "arm,armv8-timer";
-		interrupts = <GIC_PPI 13 (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_LOW)>, /* Physical Secure */
-			     <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_LOW)>, /* Physical Non-Secure */
-			     <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_LOW)>, /* Virtual */
-			     <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_LOW)>; /* Hypervisor */
+		interrupts = <GIC_PPI 13 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>, /* Physical Secure */
+			     <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>, /* Physical Non-Secure */
+			     <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>, /* Virtual */
+			     <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>; /* Hypervisor */
 		clock-frequency = <8000000>;
 		arm,no-tick-in-suspend;
 	};