Neon version of OverdriveAndSuppress()

audioproc reports the average frame time going from 279us to 255us with the test data used.

the output does not match the c version, but the difference seen is +-1.

Performance gain on Nexus7: 8.8%

BUG=3131
TESTED=trybots and manually
R=bjornv@webrtc.org, cd@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/19539004

Patch from Scott LaVarnway <slavarnw@gmail.com>.

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6433 4adac7df-926f-26a2-2b94-8c16560cd09d