msm: kgsl: unload/reload zap shader

Unload zap shader during device hibernation and reload it
during resume otherwise scm calls during post hibernation
GPU initialization will fail as there is possibility that
TZ driver is not aware of the hibernation.

Change-Id: I1f62fb97cbc8e6c3e3536d4d5260a543ca15b685
Signed-off-by: Suprith Malligere Shankaregowda <supgow@codeaurora.org>
Signed-off-by: Thomas Yun <wyun@codeaurora.org>