RM9000 support was removed a while ago but this bit crept back in through
commit 69f24d17 [MIPS: Optimize current_cpu_type() for better code.] which
had been developed before but merged after RM9000 support was removed.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Reported-by: Paul Bolle <pebolle@tiscali.nl>