ASoC: msm8x16: update external PA on secondary MI2S

Update machine driver with different functions for SEC
MI2S interface BE, which will cleanly enable the params
required for the respective BE.

CRs-Fixed: 673156
Change-Id: Iac61cd96314cb76e05d607b7a50370ac705bf5af
Signed-off-by: Aravind Kumar <akumark@codeaurora.org>