arm64: zynqmp: Add missing mmc aliases in ep108

Add missing mmc aliases.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm64/boot/dts/xilinx/zynqmp-ep108.dts

@@ -20,6 +20,8 @@ / {
 	model = "ZynqMP EP108";
 
 	aliases {
+		mmc0 = &sdhci0;
+		mmc1 = &sdhci1;
 		serial0 = &uart0;
 	};