hwrng: st: dt: Fix trivial typo in node address

DT nodes should not append their addresses with '0x'.
Suggested-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Documentation/devicetree/bindings/rng/st,rng.txt

@@ -8,7 +8,7 @@ clocks		: Phandle to device's clock (See: ../clocks/clock-bindings.txt)
 
 Example:
 
-rng@0xfee80000 {
+rng@fee80000 {
 	compatible      = "st,rng";
 	reg		= <0xfee80000 0x1000>;
 	clocks          = <&clk_sysin>;