powerpc: mpc8xx_pic: Cleanup flow type handling

The core irq_set_type() function updates the flow type when the chip
callback returns 0. So setting the type is bogus. The level flag is
updated in the core as well.

Use the proper accessors for setting the irq handlers.

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