msm: kgsl: Do not detect faults when GPU core is idle

Do not detect GPU faults when GPU hardware status is idle,
this leads to incorrect fault detection.

Conflicts:
	drivers/gpu/msm/adreno.h

Change-Id: I7a9f8c49eb819241698f99fd50aaed400aadd4f4
Signed-off-by: Tarun Karra <tkarra@codeaurora.org>
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>
(cherry picked from commit 8002a0061d3ccfeccb93af50bce4ef44977845af)
msm: hotplug: Honor enabled toggle

Start workqueue only if enabled. Also queue remove down
lock work on cpu0, circumvent regular cpu down routine
when disabling hotplug work and remove complete nonsense
in store_min_cpus_online().