ANDROID: mm: do not allow file-backed pages from CMA

Android has carried custom patches not allowing file-backed page
allocation from CMA area since it could cause CMA allocation
failure/slowness. However, Compaction could allow migrating
file-backed pages to CMA area so causes CMA allocation's trouble.

This patch checks whether there are file-backed migration source
pages or not in compaction. If there are, compaction allows only
MIGRATE_MOVABLE's pageblock, not MIGRATE_CMA's one for selecting
migration target pages(i.e., free pages).

[surenb: original patch reworked using compact_control_ext to avoid
breaking frozen ABI]

Bug: 207498240
Bug: 305594365
Change-Id: Ibf30eea6bf24aafa2a75a73cef6084b1c837bd06
Signed-off-by: Minchan Kim <minchan@google.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>