ASoC: msm: Fix for Voice2 Call

PRI_I2S_TX was being used for voice2
call, which is not supported on 8x10.
Thus, voice2 call could not be established.
We need to use PRI_MI2S_TX instead for
voice2, and add PRI_MI2S_TX mixer controls
for Voice2 session in msm-pcm-routing-v2.

CRs-fixed: 504307
Change-Id: Ibafa478b02ca32297441b9a1f7facda806263141
Signed-off-by: Vicky Sehrawat <vickys@codeaurora.org>