PCI: pciehp: Remove pciehp_debug uses

We're about to convert pciehp to the dyndbg mechanism, which means we can
eventually remove pciehp_debug.

Replace uses of pciehp_debug with dbg() and ctrl_dbg(), which check
pciehp_debug internally.

Link: https://lore.kernel.org/lkml/20190509141456.223614-6-helgaas@kernel.org


Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>