Revert "msm8226-common: Don't activate ZRAM"

This reverts commit d86adc74dba60229d3dba001312e1e15f3a3a697.

Change-Id: I2121d3a23ab367fc9e919d8b1deca284b1960d71
msm8226-common: Remove unused zcache flag

* zcache isn't generally available on ARM kernels.

Change-Id: Iea907ef80e4ff83cee9e30dbe00b2f1667c8982c