soc/amd/stoneyridge: Add IOMMU support

Enable the IOMMU in AGESA and copy the AGESA generated IVRS ACPI table.

BUG=b:116196614
TEST=Check dmesg for AMD-Vi messages.

Change-Id: I688d867c7bd4949a57b27c1b6a793c6a6e4a717a
Signed-off-by: Marc Jones <marc.jones@scarletltd.com>
Reviewed-on: https://review.coreboot.org/28753
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Martin Roth <martinroth@google.com>

src/soc/amd/stoneyridge/northbridge.c

@@ -508,7 +508,7 @@ __weak void set_board_env_params(GNB_ENV_CONFIGURATION *params) { }
 
 void SetNbEnvParams(GNB_ENV_CONFIGURATION *params)
 {
-	params->IommuSupport = FALSE;
+	params->IommuSupport = TRUE;
 	set_board_env_params(params);
 }