arm: ls1021a: Enable CONFIG_DM_USB in defconfigs

Enables driver model flag CONFIG_DM_USB for LS1021A
platform defconfigs.

Signed-off-by: Rajesh Bhagat <rajesh.bhagat@nxp.com>
diff --git a/configs/ls1021aqds_nor_defconfig b/configs/ls1021aqds_nor_defconfig
index 6748546..7a82c67 100644
--- a/configs/ls1021aqds_nor_defconfig
+++ b/configs/ls1021aqds_nor_defconfig
@@ -29,3 +29,4 @@
 CONFIG_USB=y
 CONFIG_USB_XHCI_HCD=y
 CONFIG_USB_XHCI_DWC3=y
+CONFIG_DM_USB=y