parisc: fix redefinition of SET_PERSONALITY
commit e72837e3e7bae3f182c4ac63c9424e86f1158dd0 introduced
a default SET_PERSONALITY() in include/linux/elf.h.
This breaks with our own SET_PERSONALITY define for
32bit userspace on 64bit kernel.
Signed-off-by: Helge Deller <deller@gmx.de>