fb: add support for drivers not needing VT switch at suspend/resume time

Use the new PM routines to indicate whether we need to VT switch at suspend
and resume time.  When a new driver is bound, set its flag accordingly,
and when unbound, remove it from the PM's console tracking list.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>