m68k/mac: Clean up interrupt debug macros and printk statements

Mac interrupt code has been debugged. The Penguin deficiencies that
still cause unhandled interrupts aren't fixable here. Besides,
interrupts are fast and frequent and these printk statements
were never really useful IMO. Remove them.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>