[Feature][ZXW-222] Add set voice dtmf api

Only Configure: No
Affected branch: master
Affected module: call
Is it affected on both ZXIC and MTK:only zxic
Self-test: Yes
Doc Update:Yes

Change-Id: Ia35e6787e4ad6f6d4a94e4d5d14967d78aa03a9a
3 files changed