irqchip/irq-bcm7120-l2: Add put_device() after of_find_device_by_node()

irqchip/irq-bcm7120-l2: Add put_device() after of_find_device_by_node()

This was found by coccicheck:
./drivers/irqchip/irq-bcm7120-l2.c,328,1-7,ERROR  missing put_device;
call of_find_device_by_node on line 234, but without a corresponding
object release within this function.
./drivers/irqchip/irq-bcm7120-l2.c,341,1-7,ERROR  missing put_device;
call of_find_device_by_node on line 234, but without a corresponding
object release within this function.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Ye Guojin <ye.guojin@zte.com.cn>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211109055958.130287-1-ye.guojin@zte.com.cn