qcacmn: Add callback for dynamic changes to current channel list

For dynamic master channel list, compute per pdev current channel
list as well. Provide API for user to register callback to be called
whenever current channel list for a pdev changes.

CRs-Fixed: 2012415
Change-Id: Ie86a719306178a1c3579c2b534a52a12ec3e0b1d
9 files changed