brcm80211: update PCI config space define

- replaced sizeof(struct pci_config_regs) with exact size; removed
  struct
- cleaned up the rest of broadcom PCI specific defines

Signed-off-by: Stanislav Fomichev <kernel@fomichev.me>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>