PowerHAL: Adds the low power mode power hint.

Low Power Mode power hint caps the maximum frequency.
It also reduces the refresh rate by making service call to the
SurfaceFlinger.
In case of hot plugged cpu, the max frequency is set when the cpu is
hotplugged in, using uevent notification.

Change-Id: Id78fbd765b36785d8ecdfee26d6299b39cad2874
Signed-off-by: Ruchi Kandoi<kandoiruchi@google.com>
2 files changed