am335x_evm: do not define usb ether gadget when Eth DM is defined

Since usb ether gadget doesn't have support for driver model, so
not defining usb ether gadget when ethernet driver model is
defined.

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

include/configs/am335x_evm.h

@@ -338,9 +338,12 @@
 #endif
 
 #ifdef CONFIG_USB_MUSB_GADGET
+/* Removing USB gadget and can be enabled adter adding support usb DM */
+#ifndef CONFIG_DM_ETH
 #define CONFIG_USB_ETHER
 #define CONFIG_USB_ETH_RNDIS
 #define CONFIG_USBNET_HOST_ADDR	"de:ad:be:af:00:00"
+#endif /* CONFIG_DM_ETH */
 
 /* USB TI's IDs */
 #define CONFIG_G_DNL_VENDOR_NUM 0x0451