riscv: dts: microchip: use vendor compatible for Cadence SD4HC

Licensed IP blocks should have their own vendor compatible.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

arch/riscv/boot/dts/microchip/microchip-mpfs.dtsi

@@ -264,7 +264,7 @@ serial3: serial@20104000 {
 
 		/* Common node entry for emmc/sd */
 		mmc: mmc@20008000 {
-			compatible = "cdns,sd4hc";
+			compatible = "microchip,mpfs-sd4hc", "cdns,sd4hc";
 			reg = <0x0 0x20008000 0x0 0x1000>;
 			interrupt-parent = <&plic>;
 			interrupts = <88 89>;