acpu: add cpu underclock

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>
defconfig: enable cpu underclock

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>
msm_dcvs: Increase max freqs

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>