Add support for DMP Vortex86EX PCI northbridge.

Change-Id: I60675a357f9db430ebb59b17be6d8c92a9cadf43
Signed-off-by: Andrew Wu <arw@dmp.com.tw>
Reviewed-on: http://review.coreboot.org/3511
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/src/northbridge/Makefile.inc b/src/northbridge/Makefile.inc
index 283ba4e..1a5b1c8 100644
--- a/src/northbridge/Makefile.inc
+++ b/src/northbridge/Makefile.inc
@@ -1,4 +1,5 @@
 subdirs-y += amd
+subdirs-y += dmp
 subdirs-y += intel
 subdirs-y += rdc
 subdirs-y += via