staging: gasket: core: move core PCI calls to device drivers

Remove gasket wrapping of PCI probe, enable, disable, and remove
functions.  Replace with calls to add and remove PCI gasket devices,
to be called by the gasket device drivers.

Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>