Minor updates to AudioEncoderCng

Removing sample_rate_hz_ from AudioEncoderCng and from the config
struct. The sample rate will now be read from the underlying speech
codec.

BUG=3926
COAUTHOR:kwiberg@webrtc.org

R=tina.legrand@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/40559004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@8173 4adac7df-926f-26a2-2b94-8c16560cd09d
3 files changed