ANDROID: sched: Add support for frequency/power energy model

This patch provides support to pass frequency/power values from energy
model instead of capacity/power. It is required to support multiple
speed bin devices i.e. devices which have different max frequency based
on hardware.

User can provide all supported frequencies across all versions of the
device in device tree energy model. Max frequency of the cpu is read
at runtime from OPP driver and the capacity values are populated
using that. Energy model proc file will display cap_states as a tuple of
(capacity, frequency, power), in which frequency will be 0 when not using
frequency energy model.

Change-Id: I25aec1f91aa8f09bcf67f0575792693808847618
Signed-off-by: Puja Gupta <pujag@codeaurora.org>