Let plugins hook into service startup to notify 3rd party daemon.

This commit adds support for calling plugin hooks when all services
have been started properly. Useful for, e.g., a 3rd party service
monitor to trigger further events on.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

plugin.h

@@ -42,6 +42,7 @@ typedef enum {
 	HOOK_BASEFS_UP = 0,
 	HOOK_NETWORK_UP,
 	HOOK_SYSTEM_UP,
+	HOOK_SVC_UP,
 	HOOK_SHUTDOWN,
 	HOOK_MAX_NUM
 } hook_point_t;