dt-bindings: Documentation for qcom, llcc

Documentation for last level cache controller device tree bindings,
client bindings usage examples.
Signed-off-by: Channagoud Kadabi <ckadabi@codeaurora.org>
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>

Documentation/devicetree/bindings/arm/msm/qcom,llcc.txt

+== Introduction==
+
+LLCC (Last Level Cache Controller) provides last level of cache memory in SOC,
+that can be shared by multiple clients. Clients here are different cores in the
+SOC, the idea is to minimize the local caches at the clients and migrate to
+common pool of memory. Cache memory is divided into partitions called slices
+which are assigned to clients. Clients can query the slice details, activate
+and deactivate them.
+
+Properties:
+- compatible:
+	Usage: required
+	Value type: <string>
+	Definition: must be "qcom,sdm845-llcc"
+
+- reg:
+	Usage: required
+	Value Type: <prop-encoded-array>
+	Definition: Start address and the the size of the register region.
+
+Example:
+
+	cache-controller@1100000 {
+		compatible = "qcom,sdm845-llcc";
+		reg = <0x1100000 0x250000>;
+	};