ARM: dts: msm: replace capacity with frequency in sched-energy for sdm845

Energy model now takes CPU's frequency steps in lieu of capacities to
support various speednbins.  Replace capacities with CPU frequency
table.

Also add frequency steps and corresponding power cost for speedbin 1
and 2.

Change-Id: I7cd7c2d56a4a173dac014df5feca1c64736c3c1f
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>