soc/intel/denverton_ns: Add Denverton-AD system agent id

This is to add support for Denverton-AD soc.

Change-Id: I539abedd65bcbdb97b64f58d0b2273ff8eb67420
Signed-off-by: Lew, Chee Soon <chee.soon.lew@intel.com>
Reviewed-on: https://review.coreboot.org/22605
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
diff --git a/src/soc/intel/denverton_ns/systemagent.c b/src/soc/intel/denverton_ns/systemagent.c
index bb5f81a..0fcac3b 100644
--- a/src/soc/intel/denverton_ns/systemagent.c
+++ b/src/soc/intel/denverton_ns/systemagent.c
@@ -346,6 +346,7 @@
 /* IDs for System Agent device of Intel Denverton SoC */
 static const unsigned short systemagent_ids[] = {
 	SA_DEVID, /* DVN System Agent */
+	SA_DEVID_DNVAD, /* DVN-AD System Agent */
 	0
 };