irq_of_parse_and_map() returns 0 on error, while the code checks for NO_IRQ.
This breaks on platforms that have NO_IRQ != 0.

Cc: <stable@vger.kernel.org>
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>