ANDROID: mm: Avoid merging cma with others

MIGRATE_CMA is incorrectly considered as mergeable since
433445e9 ("ANDROID: mm: add cma pcp list"), which moves the
MIGRATE_PCPTYPES enum after MIGRATE_CMA.

This causes incorrect CMA accounting with CmaFree greater than CmaTotal.
  CmaTotal:         307200 kB
  CmaFree:          314100 kB

The problem is observed when running the CtsAutoFillServiceTestCases
module with mem=2G, cma=300M, swap(zram)=600M.

And this issue is caused by the combination of
433445e9 ("ANDROID: mm: add cma pcp list") and
1dd214b8 ("mm: page_alloc: avoid merging non-fallbackable pageblocks
with others") which was introduced in 5.18 kernel.

Bug: 282793501
Fixes: 433445e9 ("ANDROID: mm: add cma pcp list")
Signed-off-by: Haoran.Wang <elven.wang@nxp.com>
Signed-off-by: Jindong Yue <jindong.yue@nxp.com>
Change-Id: I9bf705984682f29b2a23ba38536e667617b1a8b6