arm64: dts: imx93: correct s4mu interrupt names

Per binding doc, interrupt names should be tx and rx.

Fixes: 0dfb380d ("arm64: dts: imx93: add s4 mu node")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx93.dtsi

@@ -501,7 +501,7 @@ s4muap: mailbox@47520000 {
 			reg = <0x47520000 0x10000>;
 			interrupts = <GIC_SPI 31 IRQ_TYPE_LEVEL_HIGH>,
 				     <GIC_SPI 30 IRQ_TYPE_LEVEL_HIGH>;
-			interrupt-names = "txirq", "rxirq";
+			interrupt-names = "tx", "rx";
 			#mbox-cells = <2>;
 		};