MIPS: Drop EXPERIMENTAL tag from O32+FP64 & MSA

CONFIG_MIPS_O32_FP64_SUPPORT and CONFIG_CPU_HAS_MSA are in pretty good
shape these days, and in much wider use than they once were. Stop
referring to them as EXPERIMENTAL.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10801/


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