ASoC: msm: fix hfp client call failure

HFP client call fails due to absence of dpcm playback flag
in the backend DAI link. Add the flag to fix the issue and
change the name of the DAI link to avoid confusion that it
supports only capture.

Change-Id: I0bd83eaba7fa2aa8ed567acc6344876163353f20
Signed-off-by: Satya Krishna Pindiproli <satyak@codeaurora.org>