arm64: dts: imx8mp: Add imx8mp-specific irqsteer compatible

i.MX8MP irqsteer has power-domain support, so use a dedicated compatible.
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mp.dtsi

@@ -1949,7 +1949,7 @@ hdmi_blk_ctrl: blk-ctrl@32fc0000 {
 			};
 
 			irqsteer_hdmi: interrupt-controller@32fc2000 {
-				compatible = "fsl,imx-irqsteer";
+				compatible = "fsl,imx8mp-irqsteer", "fsl,imx-irqsteer";
 				reg = <0x32fc2000 0x1000>;
 				interrupts = <GIC_SPI 43 IRQ_TYPE_LEVEL_HIGH>;
 				interrupt-controller;