usb: s3c-otg: Rename sources to dwc2_*c

The driver is actually for the Designware DWC2 controller.
This patch renames the local source files to dwc2_*c and
adjusts the Makefile to use the new names.

Signed-off-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/gadget/Makefile b/drivers/usb/gadget/Makefile
index 6288ecf..dd4df00 100644
--- a/drivers/usb/gadget/Makefile
+++ b/drivers/usb/gadget/Makefile
@@ -13,8 +13,8 @@
 obj-$(CONFIG_USB_GADGET_AT91) += at91_udc.o
 obj-$(CONFIG_USB_GADGET_ATMEL_USBA) += atmel_usba_udc.o
 obj-$(CONFIG_USB_GADGET_BCM_UDC_OTG_PHY) += bcm_udc_otg_phy.o
-obj-$(CONFIG_USB_GADGET_S3C_UDC_OTG) += s3c_udc_otg.o
-obj-$(CONFIG_USB_GADGET_S3C_UDC_OTG_PHY) += s3c_udc_otg_phy.o
+obj-$(CONFIG_USB_GADGET_S3C_UDC_OTG) += dwc2_udc_otg.o
+obj-$(CONFIG_USB_GADGET_S3C_UDC_OTG_PHY) += dwc2_udc_otg_phy.o
 obj-$(CONFIG_USB_GADGET_FOTG210) += fotg210.o
 obj-$(CONFIG_CI_UDC)	+= ci_udc.o
 obj-$(CONFIG_USB_GADGET_DOWNLOAD) += g_dnl.o