PCI: Remove unnecessary __ref annotations

PCI: Remove unnecessary __ref annotations

Some PCI functions used to be marked __devinit.  When CONFIG_HOTPLUG was
not set, these functions were discarded after boot.  A few callers of these
__devinit functions were marked __ref to indicate that they could safely
call the __devinit functions even though the callers were not __devinit.

But CONFIG_HOTPLUG and __devinit are now gone, and the need for the __ref
annotations is also gone, so remove them.  Relevant historical commits:

  b40cb13ef7f3 Remove __dev* markings from init.h
  d8c602fadd3e PCI: add generic pci_hp_add_bridge()
  747fe63597d9 PCI: fix section mismatch warning in pci_scan_child_bus
  d146e16ade85 PCI: fix 4x section mismatch warnings

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>