msm: kgsl: Do not crash on context detach timeout failure

If context wait for global timeouts in detach path there is
no use to process its pending commands. Hence to handle context
detach timeout failure, invalidate the context and remove all
the pending commands from that context. So that other context
commands proceed successfully after the context detach timeout
fault recovery.

Change-Id: Ie4ff0ed5d08312d345b248a2404ce085552b0b09
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>
Signed-off-by: Lynus Vaz <lvaz@codeaurora.org>