Activate the IOMMU for the ASUS F2A85-M LE board.
Enable the IOMMU in `devicetree.cb` and build AGESA IOMMU code by
enabling the option in `buildOpts.c`.
ACPI and MPTABLES interrupt routers are already present since they are
syminks to the F2A85-M version.
```
$ uname -a
Linux nukunuku 4.8.5 #35 SMP Sun Oct 30 19:34:55 CET 2016 x86_64 GNU/Linux
$ lspci -s 0.2
00:00.2 IOMMU: Advanced Micro Devices, Inc. [AMD] Family 15h (Models 10h-1fh) I/O Memory Management Unit
$ dmesg | grep -i IOMMU
ACPI: IVRS 0x00000000BFFAFF70 000070 (v02 AMD AMDIOMMU 00000001 AMD 00000000)
AMD-Vi: Applying erratum 746 workaround for IOMMU at 0000:00:00.2
iommu: Adding device 0000:00:01.0 to group 0
[...]
iommu: Adding device 0000:00:18.5 to group 9
iommu: Adding device 0000:03:00.0 to group 8
AMD-Vi: Found IOMMU at 0000:00:00.2 cap 0x40
AMD IOMMUv2 driver by Joerg Roedel <jroedel@suse.de>
```
BUG=none
BRANCH=none
TEST=none
Change-Id: I3c758fb32becec6c5752a9e76af6345f37645078
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 31db6f5e17
Original-Change-Id: I6049fcfad53d16a99495d7a8fbc584c71e371d73
Original-Signed-off-by: Tobias Diedrich <ranma+coreboot@tdiedrich.de>
Original-Reviewed-on: https://review.coreboot.org/18259
Original-Tested-by: build bot (Jenkins)
Original-Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Original-Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://chromium-review.googlesource.com/437465
176dfceff5