usb: s3c-otg: Tweak the comments

The driver is actually for the Designware DWC2 controller.
Tweak the comments in the driver to reflect this fact.

Signed-off-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/gadget/dwc2_udc_otg_phy.c b/drivers/usb/gadget/dwc2_udc_otg_phy.c
index eedfe37..d3e9840 100644
--- a/drivers/usb/gadget/dwc2_udc_otg_phy.c
+++ b/drivers/usb/gadget/dwc2_udc_otg_phy.c
@@ -1,6 +1,6 @@
 /*
  * drivers/usb/gadget/dwc2_udc_otg.c
- * Samsung S3C on-chip full/high speed USB OTG 2.0 device controllers
+ * Designware DWC2 on-chip full/high speed USB OTG 2.0 device controllers
  *
  * Copyright (C) 2008 for Samsung Electronics
  *