greybus: svc: Remove unused declarations

Commit 84427943d2da ("greybus: svc: drop legacy-protocol dependency")
removed these implementations but not the declarations.

Signed-off-by: Yue Haibing <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

include/linux/greybus/svc.h

···
 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 */