PNP: in debug resource dump, make empty list obvious

If the resource list is empty, say that explicitly.  Previously,
it was confusing because often the heading was followed by zero
resource lines, then some "add resource" lines from auto-assignment,
so the "add" lines looked like current resources.

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