- Remove sys/cdefs.h header. - Make use of pci_matchbyid(). - Replace magic number with PCI_MAPREG_START for the PCI BAR. - Remove redundant code to enable PCI bus mastering which is already   dealt with by pci_mapreg_map().
- Remove sys/cdefs.h header.
- Make use of pci_matchbyid().
- Replace magic number with PCI_MAPREG_START for the PCI BAR.
- Remove redundant code to enable PCI bus mastering which is already
  dealt with by pci_mapreg_map().

ok mikeb@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars