Add ZRAM and change cpufred.c to set max and min clock speed by default.

ZRAM pick from Liquid Smooth
https://github.com/LiquidSmooth-Devices/android_kernel_htc_msm8974/commit/a8836261ca21ec5296cb354472ee4f321f098b72

Change-Id: Ic57f163c01f79ac2aee28f5a1dd1c63faf32fd86