ASoC: msm: qdsp6v2: Fix gapless session open fail

During gapless playback, next track open write
command is triggered to DSP. At the same time,
for current track, volume change or some PP command
is triggered to DSP. Due to race condition, the track
open write fails since the second command is
triggered asynchronously. Use separate cmd state
for PP command to handle this.

CRs-Fixed: 1080766
Change-Id: Ia80766394e4933800b72be2bf3296cd5de4e3159
Signed-off-by: Laxminath Kasam <lkasam@codeaurora.org>