ASoC: msm: use list function to access PCM runtime nodes

ASoC has replaced the PCM runtime array with a linked list.
Update MSM drivers to use list operations to access the
runtime nodes for the platform.
These changes are in accordance with the upstream changes
in ASoC between Linux-4.4 and Linux-4.9 versions.

Change-Id: I96dcb282eaae1999d583e7a98f6b2748df5a35c8
Signed-off-by: Banajit Goswami <bgoswami@codeaurora.org>