soc/amd/*: Hook up IOMMU ops in devicetree

This removed the need to maintain a PCI driver.

Change-Id: I43def81d615749008fcc9de8734fa2aca752aa9d
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/68146
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martin.roth@amd.corp-partner.google.com>
diff --git a/src/soc/amd/stoneyridge/chipset_st.cb b/src/soc/amd/stoneyridge/chipset_st.cb
index 286bb8a..4d9af90 100644
--- a/src/soc/amd/stoneyridge/chipset_st.cb
+++ b/src/soc/amd/stoneyridge/chipset_st.cb
@@ -7,7 +7,7 @@
 	device domain 0 on
 		ops stoneyridge_pci_domain_ops
 		device pci 00.0 alias gnb on ops stoneyridge_northbridge_operations end
-		device pci 00.2 alias iommu off end
+		device pci 00.2 alias iommu off ops amd_iommu_ops end
 		device pci 01.0 alias gfx off end # internal GPU
 		device pci 01.1 alias gfx_hda off end # display HD Audio controller
 		device pci 02.0 on end # Dummy Host Bridge, do not disable