mm: change lmk/cma using policy [1/1]

mm: change lmk/cma using policy [1/1]

PD#TV-10462

Problem:
Memory will allocation fail if play secure vedio source. Usually
seen by zram/wifi driver

Solution:
1, wake up kswapd earlier if water mark without free cma is not ok;
2, using zone-filecache to increace active of lmk. Which can be more
accurate than using global page status;
3, remove some restrict of using cma when allocate movable page by
zram or migrate from cma pool;
4, try allocate hard for atomic request in soft IRQ

Verify:
T950L

Change-Id: Ibf03f3c11a32175e9983ee8a61a14ae4b2436f1e
Signed-off-by: Tao Zeng <tao.zeng@amlogic.com>