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/configs/db-mv784mp-gp_defconfig b/configs/db-mv784mp-gp_defconfig
index df17dba..258e4d6 100644
--- a/configs/db-mv784mp-gp_defconfig
+++ b/configs/db-mv784mp-gp_defconfig
@@ -5,6 +5,11 @@
 CONFIG_SPL=y
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set
+CONFIG_CMD_USB=y
 # CONFIG_CMD_SETEXPR is not set
 CONFIG_NAND_PXA3XX=y
 CONFIG_SPI_FLASH=y
+CONFIG_USB=y
+CONFIG_DM_USB=y
+CONFIG_USB_EHCI_HCD=y
+CONFIG_USB_STORAGE=y