audio msm8974: new path for speaker phone with AEC

Added new path for voice/video chat mic when AEC is on
in speakerphone mode to allow different gain settings from
speakerphone in telephony.

Bug: 13279002.
Change-Id: If8f76c243f2bf8b5defae35ecf871510cc6fe41d
Merge tag 'android-4.4.3_r1' into kitkat

Android 4.4.3 release 1

# gpg: error loading `iconv.dll': The specified module could not be found.
#
# gpg: please see http://www.gnupg.org/download/iconv.html for more information
# gpg: Signature made 06/02/14 14:32:51 using DSA key ID 9AB10E78
# gpg: Can't check signature: public key not found