msm8660-common: use MAX_FREQ_LIMIT from cpufreq.h

 Instead of hard coding and duplicate logic, use the defined
 max frequency from the header file instead.

Change-Id: I52053818c526d6e2295844b7d605a8f35c3fea46
Merge branch 'cm-10.2' of git://github.com/CyanogenMod/android_kernel_samsung_msm8660-common into cm-10.2
GPU OC