usb: net: don't ifdef routine declarations in usb_ether.h

while compilation of implemented routines and references from calling
sites may be optional, declarations in header files should not be

unconditionally declare the Asix and SMSC related public USB ethernet
driver routines in the usb_ether.h header file

Signed-off-by: Gerhard Sittig <gsi@denx.de>
Acked-by: Simon Glass <sjg@chromium.org>
Acked-by: Marek Vasut <marex@denx.de>

include/usb_ether.h

@@ -40,23 +40,19 @@ struct ueth_data {
 };
 
 /*
- * Function definitions for each USB ethernet driver go here, bracketed by
- * #ifdef CONFIG_USB_ETHER_xxx...#endif
+ * Function definitions for each USB ethernet driver go here
+ * (declaration is unconditional, compilation is conditional)
  */
-#ifdef CONFIG_USB_ETHER_ASIX
 void asix_eth_before_probe(void);
 int asix_eth_probe(struct usb_device *dev, unsigned int ifnum,
 		      struct ueth_data *ss);
 int asix_eth_get_info(struct usb_device *dev, struct ueth_data *ss,
 		      struct eth_device *eth);
-#endif
 
-#ifdef CONFIG_USB_ETHER_SMSC95XX
 void smsc95xx_eth_before_probe(void);
 int smsc95xx_eth_probe(struct usb_device *dev, unsigned int ifnum,
 			struct ueth_data *ss);
 int smsc95xx_eth_get_info(struct usb_device *dev, struct ueth_data *ss,
 			struct eth_device *eth);
-#endif
 
 #endif /* __USB_ETHER_H__ */