parisc: remove obsolete manual allocation aligning in iosapic

kmalloc() returns memory with __assume_kmalloc_alignment, which is
__alignof__(unsigned long long) for parisc.

Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Helge Deller <deller@gmx.de>