Add X-Gene SoC RNG driver documentation.
Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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+APM X-Gene SoC random number generator.
+
+Required properties:
+
+- compatible  : should be "apm,xgene-rng"
+- reg         : specifies base physical address and size of the registers map
+- clocks      : phandle to clock-controller plus clock-specifier pair
+- interrupts  : specify the fault interrupt for the RNG device
+
+Example:
+
+       rng: rng@10520000 {
+               compatible = "apm,xgene-rng";
+               reg = <0x0 0x10520000 0x0 0x100>;
+               interrupts =   <0x0 0x41 0x4>;
+               clocks = <&rngpkaclk 0>;
+       };