Use enum for target_register_timer_callback()

Change-Id: I268e8c5d783914aa97cbde301448b2c5bc3cb9e6
Signed-off-by: Marc Schink <openocd-dev@marcschink.de>
Reviewed-on: http://openocd.zylin.com/4921
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>

src/target/target.c

@@ -1357,7 +1357,7 @@ static int target_init(struct command_context *cmd_ctx)
 		return retval;
 
 	retval = target_register_timer_callback(&handle_target,
-			polling_interval, 1, cmd_ctx->interp);
+			polling_interval, TARGET_TIMER_TYPE_PERIODIC, cmd_ctx->interp);
 	if (ERROR_OK != retval)
 		return retval;