usb: s3c-otg: Zap useless externs

The extern statements are useless, remove them. Also remove the
extern ... controller, which is completely useless.
Signed-off-by: NMarek Vasut <marex@denx.de>

drivers/usb/gadget/s3c_udc_otg_priv.h

@@ -88,13 +88,11 @@ struct dwc2_udc {
 	unsigned req_pending:1, req_std:1;
 };
 
-extern struct dwc2_udc *the_controller;
-
 #define ep_is_in(EP) (((EP)->bEndpointAddress&USB_DIR_IN) == USB_DIR_IN)
 #define ep_index(EP) ((EP)->bEndpointAddress&0xF)
 #define ep_maxpacket(EP) ((EP)->ep.maxpacket)
 
-extern void otg_phy_init(struct dwc2_udc *dev);
-extern void otg_phy_off(struct dwc2_udc *dev);
+void otg_phy_init(struct dwc2_udc *dev);
+void otg_phy_off(struct dwc2_udc *dev);
 
 #endif	/* __S3C_UDC_OTG_PRIV__ */

include/usb/s3c_udc.h

@@ -20,6 +20,6 @@ struct s3c_plat_otg_data {
 	unsigned int	usb_gusbcfg;
 };
 
-extern int s3c_udc_probe(struct s3c_plat_otg_data *pdata);
+int s3c_udc_probe(struct s3c_plat_otg_data *pdata);
 
 #endif