Re-implement the power management.

There's two choices when fb is or isn't loaded as we treat ourselves as a
    PCI driver in the latter case.
If we are a PCI driver, then register the suspend/resume functions
    directly. If not, then we register as a sysdev and pick up the
    suspend/resume actions and pump them down into a generic *power
    function.
It'll be nice when this little mess is sorted out with regard to being a
    real PCI driver ;-/