sparc64: all pointers to irq_handler_data renamed to handler_data

In preparation of moving to use irq_data.handler_data rename
all pointers to irq_handler_data "handler_data".
This will also prevent name clash when we introduce the
new irq methods.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>