msm: kgsl: Fix recovery in case of fenced write failures

Fenced write failures are fatal i.e. they cannot be recovered from
because the fence is left in drop mode. So force set the fence to
allow mode during recovery.

Change-Id: Ib8cad3e9a4f0ef1b424df270540f424d63ff75e3
Signed-off-by: Harshdeep Dhatt <hdhatt@codeaurora.org>