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/hwlock/sprd-hwspinlock.txt

@@ -0,0 +1,23 @@
+SPRD Hardware Spinlock Device Binding
+-------------------------------------
+
+Required properties :
+- compatible : should be "sprd,hwspinlock-r3p0".
+- reg : the register address of hwspinlock.
+- #hwlock-cells : hwlock users only use the hwlock id to represent a specific
+	hwlock, so the number of cells should be <1> here.
+- clock-names : Must contain "enable".
+- clocks : Must contain a phandle entry for the clock in clock-names, see the
+	common clock bindings.
+
+Please look at the generic hwlock binding for usage information for consumers,
+"Documentation/devicetree/bindings/hwlock/hwlock.txt"
+
+Example of hwlock provider:
+	hwspinlock@40500000 {
+		compatible  = "sprd,hwspinlock-r3p0";
+		reg = <0 0x40500000 0 0x1000>;
+		#hwlock-cells = <1>;
+		clock-names = "enable";
+		clocks = <&clk_aon_apb_gates0 22>;
+	};