sparc/irq: Use access helper irq_data_get_affinity_mask()

This is a preparatory patch for moving irq_data struct members.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Link: http://lkml.kernel.org/r/1433145945-789-27-git-send-email-jiang.liu@linux.intel.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>