Merge from FreeBSD-4, revision 1.115.2.20:

Merge from FreeBSD-4, revision 1.115.2.20:

	Pin 0 on the first I/O APIC is always an ExtINT pin.  Some BIOS's are
	broken and list the type of the pin as INT rather than ExtINT in the MP
	Table.  To workaround, force pin 0 of ioapic 0 to be ExtINT if it is of
	type INT.  This is not a MFC as -current has very different apic code now.
	Current's mptable parser might need a similar workaround.

This fixes a bunch of Fujitsu machines; more information about the problem
can be viewed at:

	http://www.freebsd.org/cgi/query-pr.cgi?pr=39234

Discussed-with: 	David Rhodus <drhodus@machdep.com>
                	Matthew Dillon <dillon@backplane.com>

Test equipment was kindly provided by David Rhodus!