dt-bindings: fsl: rcpm: Add 'little-endian' and update Chassis definition

By default, QorIQ SoC's RCPM register block is Big Endian. But
there are some exceptions, such as LS1088A and LS2088A, are
Little Endian. So add this optional property to help identify
them.

Actually LS2021A and other Layerscapes won't totally follow Chassis
2.1, so separate them from powerpc SoC.
Signed-off-by: Ran Wang <ran.wang_1@nxp.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

Documentation/devicetree/bindings/soc/fsl/rcpm.txt

@@ -5,7 +5,7 @@ and power management.
 
 Required properites:
   - reg : Offset and length of the register set of the RCPM block.
-  - fsl,#rcpm-wakeup-cells : The number of IPPDEXPCR register cells in the
+  - #fsl,rcpm-wakeup-cells : The number of IPPDEXPCR register cells in the
 	fsl,rcpm-wakeup property.
   - compatible : Must contain a chip-specific RCPM block compatible string
 	and (if applicable) may contain a chassis-version RCPM compatible
@@ -20,6 +20,7 @@ Required properites:
 	* "fsl,qoriq-rcpm-1.0": for chassis 1.0 rcpm
 	* "fsl,qoriq-rcpm-2.0": for chassis 2.0 rcpm
 	* "fsl,qoriq-rcpm-2.1": for chassis 2.1 rcpm
+	* "fsl,qoriq-rcpm-2.1+": for chassis 2.1+ rcpm
 
 All references to "1.0" and "2.0" refer to the QorIQ chassis version to
 which the chip complies.
@@ -27,14 +28,19 @@ Chassis Version		Example Chips
 ---------------		-------------------------------
 1.0				p4080, p5020, p5040, p2041, p3041
 2.0				t4240, b4860, b4420
-2.1				t1040, ls1021
+2.1				t1040,
+2.1+				ls1021a, ls1012a, ls1043a, ls1046a
+
+Optional properties:
+ - little-endian : RCPM register block is Little Endian. Without it RCPM
+   will be Big Endian (default case).
 
 Example:
 The RCPM node for T4240:
 	rcpm: global-utilities@e2000 {
 		compatible = "fsl,t4240-rcpm", "fsl,qoriq-rcpm-2.0";
 		reg = <0xe2000 0x1000>;
-		fsl,#rcpm-wakeup-cells = <2>;
+		#fsl,rcpm-wakeup-cells = <2>;
 	};
 
 * Freescale RCPM Wakeup Source Device Tree Bindings
@@ -44,7 +50,7 @@ can be used as a wakeup source.
 
   - fsl,rcpm-wakeup: Consists of a phandle to the rcpm node and the IPPDEXPCR
 	register cells. The number of IPPDEXPCR register cells is defined in
-	"fsl,#rcpm-wakeup-cells" in the rcpm node. The first register cell is
+	"#fsl,rcpm-wakeup-cells" in the rcpm node. The first register cell is
 	the bit mask that should be set in IPPDEXPCR0, and the second register
 	cell is for IPPDEXPCR1, and so on.