dt-bindings: Add devicetree bindings

Add snapshot of device tree bindings from keystone common kernel, branch
"android-mainline-keystone-qcom-release" at c4c12103f9c0 ("Snap for 9228065
from e32903b9a63bb558df8b803b076619c53c16baad to
android-mainline-keystone-qcom-release").

Change-Id: I7682079615cbd9f29340a5c1f2a1d84ec441a1f1
Signed-off-by: Melody Olvera <quic_molvera@quicinc.com>

bindings/ipmi/aspeed,ast2400-ibt-bmc.txt

@@ -0,0 +1,28 @@
+* Aspeed BT (Block Transfer) IPMI interface
+
+The Aspeed SOCs (AST2400 and AST2500) are commonly used as BMCs
+(BaseBoard Management Controllers) and the BT interface can be used to
+perform in-band IPMI communication with their host.
+
+Required properties:
+
+- compatible : should be one of
+	"aspeed,ast2400-ibt-bmc"
+	"aspeed,ast2500-ibt-bmc"
+	"aspeed,ast2600-ibt-bmc"
+- reg: physical address and size of the registers
+- clocks: clock for the device
+
+Optional properties:
+
+- interrupts: interrupt generated by the BT interface. without an
+  interrupt, the driver will operate in poll mode.
+
+Example:
+
+	ibt@1e789140 {
+		compatible = "aspeed,ast2400-ibt-bmc";
+		reg = <0x1e789140 0x18>;
+		interrupts = <8>;
+		clocks = <&syscon ASPEED_CLK_GATE_LCLK>;
+	};