The Spectral module uses the first vdev of a pdev for scanning.
For MCL platforms all the vdevs are associated with a single pdev
and this may cause a mismatch between the vdev intended by user and
the vdev used by driver. To avoid this MCL platforms pass a reference
to vdev on which Spectral scan is triggered. WIN platforms
can continue to use the old approach of using the first vdev of a
pdev by passing NULL for vdev to vendor command handlers.
CRS-Fixed: 2725777
Change-Id: I1a7278bdcbcc2b706aa292b33c17546190dac082
6c76bce586