greybus: svc: Remove unused declarations

Commit 8442794 ("greybus: svc: drop legacy-protocol dependency")
removed these implementations but not the declarations.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20230818124338.37880-1-yuehaibing@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Yue Haibing

include/linux/greybus/svc.h

@@ -100,7 +100,4 @@ bool gb_svc_watchdog_enabled(struct gb_svc *svc);
 int gb_svc_watchdog_enable(struct gb_svc *svc);
 int gb_svc_watchdog_disable(struct gb_svc *svc);
 
-int gb_svc_protocol_init(void);
-void gb_svc_protocol_exit(void);
-
 #endif /* __SVC_H */