mm: upgrade KSM module to Ultra KSM v0.122

Advantages of this patch:
 - faster page scanning
 - higher succes rate of de-duplication
 - less CPU hungry daemon
 - customizable parameters through governors:
   - high
   - medium
   - low
   - quiet [default]

Now the daemon stays mostly on 0% CPU usage and rarely reaches 1-3% of CPU usage.
Those bursts of CPU usage don't affect the battery as they stay like this only for a few millisecs,
when the daemon finds pages that need de-duplication.

Change-Id: I45ebe25e772a73e7e3f3e66f409e18c79061916e
mm: uksm: lower CPU usage of the daemon

Change-Id: I6b48ad227dea6425c152093065565c283c2d02e2
binfmt_elf.c: use get_random_int() to fix entropy depleting.

Usually the entropy pool depletes very fast and stays in the 100-200 range.
After this patch, the entropy stays in the 600-1000 range without the risk of
depleting in normal workloads.

Change-Id: Ice0d0f14691046249d7b4a4d31af98ab80c6306b