MIPS: CPC: Add start, stop and running CM3 CPC registers

Add the new CM3 registers for controlling bringing up and powering down
VPs on MIPSR6 cores.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12330/


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