irqchip/atmel-aic5: Use per chip mask caches in mask/unmask()

irqchip/atmel-aic5: Use per chip mask caches in mask/unmask()

When masking/unmasking interrupts, mask_cache is updated and used later
for suspend/resume. Unfortunately, it always was the mask_cache
associated with the first irq chip which was updated. So when performing
resume, only irqs 0-31 could be enabled.

Fixes: c6b764dd859c ("irqchip: atmel-aic: Add atmel AIC/AIC5 drivers")
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Cc: <sasha.levin@oracle.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: <nicolas.ferre@atmel.com>
Cc: <alexandre.belloni@free-electrons.com>
Cc: <boris.brezillon@free-electrons.com>
Cc: <Wenyou.Yang@atmel.com>
Cc: <jason@lakedaemon.net>
Cc: <marc.zyngier@arm.com>
Cc: stable@vger.kernel.org #3.18
Link: http://lkml.kernel.org/r/1442843173-2390-1-git-send-email-ludovic.desroches@atmel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>