ASoC: msm8974: add devices for incall music delivery

Add backend DAI link and frond end DAI link to enable
incall music delivery on the second sub.
The feature is required to play LCH tone on second sub.

CRs-Fixed: 626562
Change-Id: Ibbea1e2102ea10b2d114b8d57ff96dd09863ffa1
Signed-off-by: Avinash Vaish <avaish@codeaurora.org>
Signed-off-by: Karthik Reddy Katta <a_katta@codeaurora.org>