defconfig: msm8960: enable fair group scheduler

Enable feature for CPU scheduler to recognize task
groups and schedule CPU bandwidth accordingly.
This is the mechanism used by Android to prioritize
foreground and background tasks differently,
enhancing the user experience. Though no quantifiable
improvement has yet been observed this can hopefully
be improved. No negative performance impact has
been seen.

Change-Id: I5754aed90b3d95a6ebce10c1233ed861473a504e
Signed-off-by: Vince Leung <vincentl@codeaurora.org>