arm: mvebu: Enable DM_USB on AXP / A38x boards

This patch enables DM_USB on the Marvell AXP / A38x eval boards.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Luka Perkov <luka.perkov@sartura.hr>
diff --git a/include/configs/mv-common.h b/include/configs/mv-common.h
index 92e5429..a2f60dc 100644
--- a/include/configs/mv-common.h
+++ b/include/configs/mv-common.h
@@ -128,7 +128,7 @@
 /*
  * Common USB/EHCI configuration
  */
-#ifdef CONFIG_CMD_USB
+#if defined(CONFIG_CMD_USB) && !defined(CONFIG_DM)
 #define CONFIG_USB_EHCI		/* Enable EHCI USB support */
 #define CONFIG_USB_STORAGE
 #define CONFIG_DOS_PARTITION