spl: Kconfig: Drop the _SUPPORT postfix from SPL_DFU

The symbol CONFIG_SPL_DFU_SUPPORT in SPL build has the same
meaning as CONFIG_DFU in regular U-Boot. Drop the _SUPPORT
to allow for cleaner use in code.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Acked-by: Lukasz Majewski <lukma@denx.de>
diff --git a/drivers/Makefile b/drivers/Makefile
index 4105864..14543c7 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -50,7 +50,7 @@
 obj-$(CONFIG_SPL_USB_GADGET) += usb/gadget/
 obj-$(CONFIG_SPL_USB_GADGET) += usb/common/
 obj-$(CONFIG_SPL_USB_GADGET) += usb/gadget/udc/
-obj-$(CONFIG_SPL_DFU_SUPPORT) += dfu/
+obj-$(CONFIG_SPL_DFU) += dfu/
 obj-$(CONFIG_SPL_WATCHDOG_SUPPORT) += watchdog/
 obj-$(CONFIG_SPL_USB_HOST_SUPPORT) += usb/host/
 obj-$(CONFIG_OMAP_USB_PHY) += usb/phy/