dt-bindings: ipmi: aspeed: Introduce a v2 binding for KCS

The v2 binding utilises reg and renames some of the v1 properties.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Message-Id: <8aec8994bbe1186d257b0a712e13cf914c5ebe35.1576462051.git-series.andrew@aj.id.au>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Corey Minyard <cminyard@mvista.com>

Documentation/devicetree/bindings/ipmi/aspeed-kcs-bmc.txt

-* Aspeed KCS (Keyboard Controller Style) IPMI interface
+# Aspeed KCS (Keyboard Controller Style) IPMI interface
 
 The Aspeed SOCs (AST2400 and AST2500) are commonly used as BMCs
 (Baseboard Management Controllers) and the KCS interface can be
 used to perform in-band IPMI communication with their host.
 
+## v1
 Required properties:
 - compatible : should be one of
     "aspeed,ast2400-kcs-bmc"
@@ -12,14 +13,21 @@ Required properties:
 - kcs_chan : The LPC channel number in the controller
 - kcs_addr : The host CPU IO map address
 
+## v2
+Required properties:
+- compatible : should be one of
+    "aspeed,ast2400-kcs-bmc-v2"
+    "aspeed,ast2500-kcs-bmc-v2"
+- reg : The address and size of the IDR, ODR and STR registers
+- interrupts : interrupt generated by the controller
+- aspeed,lpc-io-reg : The host CPU LPC IO address for the device
 
 Example:
 
-    kcs3: kcs3@0 {
-        compatible = "aspeed,ast2500-kcs-bmc";
-        reg = <0x0 0x80>;
+    kcs3: kcs@24 {
+        compatible = "aspeed,ast2500-kcs-bmc-v2";
+        reg = <0x24 0x1>, <0x30 0x1>, <0x3c 0x1>;
+        aspeed,lpc-reg = <0xca2>;
         interrupts = <8>;
-        kcs_chan = <3>;
-        kcs_addr = <0xCA2>;
         status = "okay";
     };