drm/msm: Disable clocks when GPU is inactive

This patch addresses an issue in the GPU init sequence where
the clocks are turned on during the process but after the
init is complete the clocks are not turned off. Due to this,
the GPU clocks always have a refcount delta of 1 and never
get disabled later even when explicitly requested.

Change-Id: I40fa9a25cd86f5d39fbe6f6e3f83d6ab467d615f
Signed-off-by: Sharat Masetty <smasetty@codeaurora.org>