PNP: make pnp_resource_table private to PNP core

There are no remaining references to the PNP_MAX_* constants or
the pnp_resource_table structure outside of the PNP core.  Make
them private to the PNP core.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>