irqchip/mtk-sysirq: Remove unnecessary barrier when configuring trigger

This prevent unnecessary visibility when configuring trigger type

Signed-off-by: Mars Cheng <[e-mail]>
Signed-off-by: Marc Zyngier <[e-mail]>

drivers/irqchip/irq-mtk-sysirq.c

···
 		value &= ~(1 << offset);
 	}
 
-	writel(value, base + reg_index * 4);
+	writel_relaxed(value, base + reg_index * 4);
 
 	data = data->parent_data;
 	ret = data->chip->irq_set_type(data, type);