MIPS: kernel: cps-vec: Replace mips32r2 ISA level with mips64r2

MIPS: kernel: cps-vec: Replace mips32r2 ISA level with mips64r2

mips32r2 is a subset of mips64r2, so we replace mips32r2 with mips64r2
in preparation for 64-bit CPS support.

Cc: <stable@vger.kernel.org> # 3.16+
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10588/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>