arm64: dts: imx8qm: Fix VPU core alias name

Alias names use dashes instead of underscores, fix this.
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8qxp.dtsi

@@ -46,9 +46,9 @@ aliases {
 		serial1 = &lpuart1;
 		serial2 = &lpuart2;
 		serial3 = &lpuart3;
-		vpu_core0 = &vpu_core0;
-		vpu_core1 = &vpu_core1;
-		vpu_core2 = &vpu_core2;
+		vpu-core0 = &vpu_core0;
+		vpu-core1 = &vpu_core1;
+		vpu-core2 = &vpu_core2;
 	};
 
 	cpus {