ARM/pxa: Prepare balloon3_irq_handler for irq argument removal

The irq argument of most interrupt flow handlers is unused or merily
used instead of a local variable. The handlers which need the irq
argument can retrieve the irq number from the irq descriptor.

While at it fix the pointless lookup of irq_data with the proper
methods to retrieve the same information from the irq descriptor.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Russell King <linux+kernel@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org