msm8660: revise cpu freqtable

* Update the voltages with the proposed S/W setting based on HW characterization data to reduce power consumption.
  Change-Id: Ib6ccdbc8a66e749223b20164ddd6490525870d57
  Signed-off-by: Tianyi Gou <tgou@codeaurora.org>
(cherry-picked from caf)

* remove 1.782GHz and add an intermediate 1.674GHz slot