AMD Fam15tn: Add IOMMU BAR allocation to northbridge

For IOMMU we need to allocate a 512 KB BAR in a non-standard
location. Use the standard allocator for that and limit the BAR
to 32-bits to be compatible with older systems.

Change-Id: I44414ce6b264b7f1c086a9b1c7ea275a0830205e
Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Signed-off-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-on: http://review.coreboot.org/3314
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
3 files changed