dt-bindings: fsl: Add LS1043A/LS1046A/LS2080A SoC compatible strings

Adds SoC compatible for LS1043A and LS2080A which are supported, and
for LS1046A which is going to be supported.
Signed-off-by: Shaohui Xie <Shaohui.Xie@nxp.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Documentation/devicetree/bindings/arm/fsl.txt

@@ -131,6 +131,10 @@ Example:
 Freescale ARMv8 based Layerscape SoC family Device Tree Bindings
 ----------------------------------------------------------------
 
+LS1043A SoC
+Required root node properties:
+    - compatible = "fsl,ls1043a";
+
 LS1043A ARMv8 based RDB Board
 Required root node properties:
     - compatible = "fsl,ls1043a-rdb", "fsl,ls1043a";
@@ -139,6 +143,14 @@ LS1043A ARMv8 based QDS Board
 Required root node properties:
     - compatible = "fsl,ls1043a-qds", "fsl,ls1043a";
 
+LS1046A SoC
+Required root node properties:
+    - compatible = "fsl,ls1046a";
+
+LS2080A SoC
+Required root node properties:
+    - compatible = "fsl,ls2080a";
+
 LS2080A ARMv8 based Simulator model
 Required root node properties:
     - compatible = "fsl,ls2080a-simu", "fsl,ls2080a";