d2lte: enable KSM

Change-Id: I47f51c50160db69bbeab45e3c1aac974a3bb3824
d2lte: add permissions for keydisabler

Change-Id: Ie5053da2473f2f62ac79320838f76b19a5551d24
Increase read-ahead to 512 KB and read ahead on mmcblk1 too

Change-Id: I4666c427d7d100327ab315e13f3f12e14ca99a70