msm: cpufreq: Add support for CPU freq. scaling for 8625

8625 has two cpu cores & both core's frequency can not
be changed independently since both run at same frequency.
Hence we set the cpumask to all cpus, hence every frequency
transition will happen for both cpu core.

Change-Id: I27dbc048abc23865c3b41c6308efc3bc64174e36
Signed-off-by: Pankaj Kumar <pakuma@codeaurora.org>