Device drivers PnP support

pnp_register_protocol — adds a pnp protocol to the pnp layer
pnp_unregister_protocol — removes a pnp protocol from the pnp layer
pnp_request_card_device — Searches for a PnP device under the specified card
pnp_release_card_device — call this when the driver no longer needs the device
pnp_register_card_driver — registers a PnP card driver with the PnP Layer
pnp_unregister_card_driver — unregisters a PnP card driver from the PnP Layer
pnp_add_id — adds an EISA id to the specified device
pnp_start_dev — low-level start of the PnP device
pnp_stop_dev — low-level disable of the PnP device
pnp_activate_dev — activates a PnP device for use
pnp_disable_dev — disables device
pnp_is_active — Determines if a device is active based on its current resources