MIPS: CPS: drop .set mips64r2 directives

MIPS: CPS: drop .set mips64r2 directives

Commit 977e043d5ea1 ("MIPS: kernel: cps-vec: Replace mips32r2 ISA level
with mips64r2") leads to .set mips64r2 directives being present in 32
bit (ie. CONFIG_32BIT=y) kernels. This is incorrect & leads to MIPS64
instructions being emitted by the assembler when expanding
pseudo-instructions. For example the "move" instruction can legitimately
be expanded to a "daddu". This causes problems when the kernel is run on
a MIPS32 CPU, as CONFIG_32BIT kernels of course often are...

Fix this by dropping the .set <ISA> directives entirely now that Kconfig
should be ensuring that kernels including this code are built with a
suitable -march= compiler flag.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: <stable@vger.kernel.org> # 3.16+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10869/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>