PCI: Apply _HPP settings to all hot-added PCI devices

We currently apply _HPP settings only to:

    - non-bridge devices, and
    - PCI-to-PCI bridges

i.e., we do not apply them to PCI-to-ISA bridges and the like.  It has been
that way since _HPP support was added by 40abb96c

 ("pciehp: Fix
programming hotplug parameters"), but I don't think there's any reason to
exclude these other bridges.

Apply _HPP settings to hot-added PCI devices of any type.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>