ARM: dts: ls1021a: reduce the interrupt-map-mask

Reduce the interrupt-map-mask of the external interrupt controller to
7 to align with the devicetree schema.
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/ls1021a.dtsi

@@ -192,7 +192,7 @@ extirq: interrupt-controller@1ac {
 					<3 0 &gic GIC_SPI 167 IRQ_TYPE_LEVEL_HIGH>,
 					<4 0 &gic GIC_SPI 168 IRQ_TYPE_LEVEL_HIGH>,
 					<5 0 &gic GIC_SPI 169 IRQ_TYPE_LEVEL_HIGH>;
-				interrupt-map-mask = <0xffffffff 0x0>;
+				interrupt-map-mask = <0x7 0x0>;
 			};
 		};