configs: add mvebu_espressobin_ultra-88f3720_defconfig

Add support for a Marvell Armada 3720 device variant

Signed-off-by: Benjamin Schneider <ben@bens.haus>
diff --git a/board/Marvell/mvebu_armada-37xx/MAINTAINERS b/board/Marvell/mvebu_armada-37xx/MAINTAINERS
index 9b0afee..e96499e 100644
--- a/board/Marvell/mvebu_armada-37xx/MAINTAINERS
+++ b/board/Marvell/mvebu_armada-37xx/MAINTAINERS
@@ -9,3 +9,8 @@
 M:	Konstantin Porotchkin <kostap@marvell.com>
 S:	Maintained
 F:	configs/mvebu_espressobin-88f3720_defconfig
+
+ESPRESSOBin Ultra BOARD
+M:	Ben Schneider <ben@bens.haus>
+S:	Maintained
+F:	configs/mvebu_espressobin_ultra-88f3720_defconfig