Revert "mm: add cma pcp list"

This reverts commit 0114d914.

That commit appears to cause corruption in drain_all_pages.
So revert it for now until we have a fix for the
corruption.

CRs-fixed: 710493
Change-Id: I96ea44f3eaaed453640a9ddeb376a4668cd87b74
Signed-off-by: Liam Mark <lmark@codeaurora.org>