hwrng: bcm2835 - Add Broadcom BCM2835 RNG driver

This adds a driver for random number generator present on Broadcom BCM2835 SoC,
used in Raspberry Pi and Roku 2 devices.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: linux-rpi-kernel@lists.infradead.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Documentation/devicetree/bindings/rng/brcm,bcm2835.txt

@@ -0,0 +1,13 @@
+BCM2835 Random number generator
+
+Required properties:
+
+- compatible : should be "brcm,bcm2835-rng"
+- reg : Specifies base physical address and size of the registers.
+
+Example:
+
+rng {
+        compatible = "brcm,bcm2835-rng";
+        reg = <0x7e104000 0x10>;
+};