msm: kgsl: use the same logic in adreno_idle and adreno_isidle

These two functions need to agree on the meaning of "idle",
so that calling adreno_isidle() right after an adreno_idle()
will always return true.

Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
(cherry picked from commit 5365240cf0abf2d799dd849abca0dc5b46d4b784)
Signed-off-by: Harsh Vardhan Dwivedi <hdwivedi@codeaurora.org>
Signed-off-by: Sridhar Gujje <sgujje@codeaurora.org>

Change-Id: I7cddf73773186c3ec8b56c111affacac3b07fcc7
msm: kgsl: Use msecs_to_jiffies for ADRENO_IDLE_TIMEOUT

This change is about to cherrypick of missing code part
from Change-Id: Ic0dedbad33630706d909931bf616bd69399f7ff1

Change-Id: I6c9766be0651e99251e1cb280f92e06e47875b4f
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>