avr32/at32ap: Use irq_set_handler_locked()

Use irq_set_handler_locked() as it avoids a redundant lookup of the
irq descriptor.

Search and replacement was done with coccinelle.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Link: http://lkml.kernel.org/r/20150713100606.448031045@linutronix.de


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