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