irqchip: gic: Simplify gic_configure_irq by using IRQCHIP_SET_TYPE_MASKED

GIC requires to disable the interrupt before changing the trigger type.
irqchip core provides IRQCHIP_SET_TYPE_MASKED flag and ensures that the
interrupt is masked before calling chip.irq_set_type() if the irqchip
sets the flag.

This patch adds IRQCHIP_SET_TYPE_MASKED to GIC irqchip so that the core
can manage disabling the interrupt while changing the trigger type.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/1433501997-19205-1-git-send-email-sudeep.holla@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>