PNP: add pnp_resource_type_name() helper function

This patch adds a "pnp_resource_type_name(struct resource *)" that
returns the string resource type.  This will be used by the sysfs
"show resources" function and the debug resource dump function.

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