Mach64 driver bails out on ia64 because it cannot map device
memory. It turns out that some bogus and unneeded code attempts
to find the root bridge of the device and fails to do so proberly
as there this host-to-pci bridge is not existant. This code has
been around for years although it completely unclear what it had
been intended for. Fixing this by eliminating the bogus code.
c1828a8ff5