ARM: dts: msm: Add the clock-a7 and cpufreq device nodes for Krypton

Add the necessary parameters for the cpu root clock generator
device. Add a list of supported frequencies for the msm-cpufreq
virtual device.

Change-Id: I0cf7912c5575a5d41e7a57ff6c2b73cf7c75fbe0
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>