Find the BBAR register address of each Calgary using the "Extended
BIOS Data Area" rather than calculating it ourselves. Also get the bus
topology (what PHB each bus is on) from Calgary rather than
calculating it ourselves.

This patch fixes http://bugzilla.kernel.org/show_bug.cgi?id=7407.
Signed-off-by: NLaurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: NMuli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>
Signed-off-by: NAndi Kleen <ak@suse.de>