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