hrcon: Add support for the DH variant

hrcon DH(dual head) has two video outputs per FPGA.

Signed-off-by: Dirk Eibach <dirk.eibach@gdsys.cc>
diff --git a/board/gdsys/mpc8308/MAINTAINERS b/board/gdsys/mpc8308/MAINTAINERS
index 35704bc..3895b01 100644
--- a/board/gdsys/mpc8308/MAINTAINERS
+++ b/board/gdsys/mpc8308/MAINTAINERS
@@ -4,6 +4,7 @@
 F:	board/gdsys/mpc8308/
 F:	include/configs/hrcon.h
 F:	configs/hrcon_defconfig
+F:	configs/hrcon_dh_defconfig
 F:	include/configs/strider.h
 F:	configs/strider_cpu_defconfig
 F:	configs/strider_con_defconfig