mfd: max8907: Remove IRQF_NO_AUTOEN flag

IRQF_NO_AUTOEN flag doesn't go well with IRQF_SHARED flag - the
check in request_threaded_irq fails and exits with EINVAL.

So we ignore the flag and enable it on the first IRQ request. No
interrupt should arrive from the chip as all interrupts are masked
by default.

Signed-off-by: Sergey Larin <cerg2010cerg2010@mail.ru>
Signed-off-by: Lee Jones <lee.jones@linaro.org>