devicetree: Add hardware rng entry to qcom-apq8064.dtsi

Add devicetree data to add support for hw_rng support
to the apq8064 dts.

Tested on the Nexus7 (2013).

Cc: Kumar Gala <galak@codeaurora.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: devicetree@vger.kernel.org
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Andy Gross <agross@codeaurora.org>