MIPS: cpu-features.h: s/MIPS53/MIPS64/

No support for MIPS53 processors yet.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5876/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>