cm: Remove legacy compcache stuff

 * Remove all this stuff.  If a device wants ZRAM, it should be
   enabled by the maintainer and properly configured and tuned.
 * This stuff currently causes a conflict with the ZRAM support
   added in Kitkat. Kill it.

Change-Id: Ib2488ea4463e32ec44b65fe786f732145b5b6e23
(cherry picked from commit 42fb9d8fc5e1bc0591a279a23f166f460bcc8c90)