audio-lnx: Fix sound card failure at stability runs

In stability reboot tests, deferred audio drivers
are not invoked after lpass loading sometimes and
results in sound card failure. Change APR to platform
device and after APR status changes to loaded state,
add dummy module child device under APR which invokes
deferred audio drivers and sound card registers successfully.

Change-Id: Ib0c0f7ec1d7dd93a1b54a9a66260861223d55c67
Signed-off-by: Laxminath Kasam <lkasam@codeaurora.org>