MIPS: MSP71xx: Add VSMP/SMTC support.

[Ralf: Fixed more checkpatch assertions and inclusion of unnecessary header
<linux/sched.h>.]

Signed-off-by: Anoop P A <anoop.pa@gmail.com>
To: linux-mips@linux-mips.org
To: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/2042/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>