is an application space macro and the applications are supposed to be free
to use it as they please (but cannot). This is consistant with the other
BSD's who made this change quite some time ago. More commits to come.
new system is integrated with the ISA bus code more cleanly and allows
the future addition of more enumerators such as PnPBIOS and ACPI.
This commit also enables the new pcm driver since it is somewhat tied to
the new PnP code.
