PCI: Unify ACS quirk desired vs provided checking

PCI: Unify ACS quirk desired vs provided checking

commit 7cf2cba43f15c74bac46dc5f0326805d25ef514d upstream.

Most of the ACS quirks have a similar pattern of:

  acs_flags &= ~( <controls provided by this device> );
  return acs_flags ? 0 : 1;

Pull this out into a helper function to simplify the quirks slightly.  The
helper function is also a convenient place for comments about what the list
of ACS controls means.  No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>