clocksource/drivers/orion: Add missing clk_disable_unprepare() on error path

After calling clk_prepare_enable(), clk_disable_unprepare() need
be called on error path.

Fixes: fbe4b3566ddc ("clocksource/drivers/orion: Convert init function...")
Reported-by: Hulk Robot <[e-mail]>
Signed-off-by: Yang Yingliang <[e-mail]>
Signed-off-by: Daniel Lezcano <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/clocksource/timer-orion.c

···
 	irq = irq_of_parse_and_map(np, 1);
 	if (irq <= 0) {
 		pr_err("%pOFn: unable to parse timer1 irq\n", np);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out_unprep_clk;
 	}
 
 	rate = clk_get_rate(clk);
···
 				    clocksource_mmio_readl_down);
 	if (ret) {
 		pr_err("Failed to initialize mmio timer\n");
-		return ret;
+		goto out_unprep_clk;
 	}
 
 	sched_clock_register(orion_read_sched_clock, 32, rate);
···
 			  "orion_event", NULL);
 	if (ret) {
 		pr_err("%pOFn: unable to setup irq\n", np);
-		return ret;
+		goto out_unprep_clk;
 	}
 
 	ticks_per_jiffy = (clk_get_rate(clk) + HZ/2) / HZ;
···
 	orion_delay_timer_init(rate);
 
 	return 0;
+
+out_unprep_clk:
+	clk_disable_unprepare(clk);
+	return ret;
 }
 TIMER_OF_DECLARE(orion_timer, "marvell,orion-timer", orion_timer_init);