MIPS: pm-cps: Select CONFIG_MIPS_CPC

MIPS: pm-cps: Select CONFIG_MIPS_CPC

The pm-cps code can run without a CPC, although will be limited to using
only the 2 wait idle states. However the code does check for CPC
presence, and in order to work optimally the CPC support is needed. So
select it.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7279/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>