gpu: nvgpu: disable channel before adjusting syncpoints

gpu: nvgpu: disable channel before adjusting syncpoints

As per current sequence in gk20a_channel_abort(),
we first balance the syncpoint values associated with
failing channel, and then abort it

Reverse this sequence so that we first disable the channel
and then only balance the syncpoints

Bug 200133289

Change-Id: I5a748afce437e728a5ff6c8a030a75d0f627c622
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/797071
(cherry picked from commit d797ddb230ed94ac565fc42377f6653fb94610a8)
Reviewed-on: http://git-master/r/806565
Signed-off-by: Thomas Fleury <tfleury@nvidia.com>
Reviewed-on: http://git-master/r/815929
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>