gpio: mvebu: Add missing breaks in mvebu_gpio_irq_set_type

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>