ASoC: msm: add stub DAIs for host pcm and DTMF detection

stub DAIs are added to support voice host pcm and
DTMF detection since no afe ports are needed to be opened.

Change-Id: I13c1c9f31702a14028e4d8bcf9db3ac7b9153aab
Signed-off-by: Helen Zeng <xiaoyunz@codeaurora.org>