greybus: greybus.h: remove greybus_svc_in()

The function is gone, remove it from the header file as well.
Tested-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/greybus.h

@@ -156,7 +156,6 @@ void greybus_deregister_driver(struct greybus_driver *driver);
 
 int greybus_disabled(void);
 
-int greybus_svc_in(struct greybus_host_device *hd, u8 *data, int length);
 void gb_debugfs_init(void);
 void gb_debugfs_cleanup(void);
 struct dentry *gb_debugfs_get(void);