dt-bindings: nvmem: Describe the Amlogic Meson6/Meson8/Meson8b efuse

Amlogic Meson6, Meson8 and Meson8b SoCs have an efuse which contains
calibration data from the factory (for the internal temperature sensor
and some CVBS connector settings). Some manufacturers also store the MAC
address or serial number in the efuse.

This documents the devicetree bindings for the efuse on these SoCs.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/nvmem/amlogic-meson-mx-efuse.txt

+Amlogic Meson6/Meson8/Meson8b efuse
+
+Required Properties:
+- compatible: depending on the SoC this should be one of:
+	- "amlogic,meson6-efuse"
+	- "amlogic,meson8-efuse"
+	- "amlogic,meson8b-efuse"
+- reg: base address and size of the efuse registers
+- clocks: a reference to the efuse core gate clock
+- clock-names: must be "core"
+
+All properties and sub-nodes as well as the consumer bindings
+defined in nvmem.txt in this directory are also supported.
+
+
+Example:
+	efuse: nvmem@0 {
+		compatible = "amlogic,meson8-efuse";
+		reg = <0x0 0x2000>;
+		clocks = <&clkc CLKID_EFUSE>;
+		clock-names = "core";
+	};