arm64: dts: ls1043a-rdb: add compatible for board

Add compatible for board to identify.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/fsl-ls1043a-rdb.dts

@@ -13,6 +13,7 @@
 
 / {
 	model = "LS1043A RDB Board";
+	compatible = "fsl,ls1043a-rdb", "fsl,ls1043a";
 
 	aliases {
 		serial0 = &duart0;