Revert "cpufreq: smartmax: Move get_cpu_idle_time() to cpufreq.c"

This reverts commit 5df400b010bd0ba5cdb4a0641eeb33504113614c.

Change-Id: Ibac6700ecadd02cdc407bfa18746eca1fba823f7
Fine tune Smartmax

Change-Id: Iadd960b92cef814cd9c3d931a0c2ce652345c477
cpufreq: cpufreq_smartmax: set global RW writeable for all and fix min_sampling_rate

Change-Id: I60069a65d05f48a45a95db124ed82643e25c21f7
Signed-off-by: Jake Weinstein <xboxlover360@gmail.com>