asoc: use virt_sndcard_ctl node for sndcard status update

In automotive hypervisor SSR case, csd2 need a while to handle resource,
hence receiving virtual SSR event doesn't mean PVM is ready for audio usecase.
AudioReach should wait for more precise events from PVM csd2.
Expose an ioctl node for updating sndcard status via gsl virtualization.

Change-Id: Ia5d1110dea970070706937c3bf5e42e1ccb1942f