ASoC: msm: fix for automotive machine driver probe failure

Add a dummy device driver which will be probed once the ADSP
is powered up. This is to ensure that the deferred audio device
drivers which depend on ADSP gets probed again after the ADSP
is powered up. The machine driver depends on these deferred
audio drivers to be successfully probed before it can register
the sound card.

This is to fix a race condition where all the kernel device
drivers (except the audio drivers that depend on ADSP) are
successfully probed before the ADSP is powered up, resulting
the audio drivers and the machine driver to remain in a
deferred state forever. The new dummy device driver will act
as a trigger for the probing of deferred drivers.

CRs-fixed: 1070694

Change-Id: I41f328b36c57a0f7e0027addddc1748357db532c
Signed-off-by: Honghao Liu <honghaol@codeaurora.org>