habanalabs: refactor fence handling in hl_cs_poll_fences

To avoid checking if fence exists multipled times, changed fence
handling to depend only on the fence status field:

Busy, which means CS still did not completed :
	Add its QID so multi CS wait on its completion.
Finished, which means CS completed and fence exists:
	Raise its completion bit if it finished mcs handling and
	update if necessary the earliest timestamp.
Gone, which means CS already completed and fence deleted:
	Update multi CS data to ignore timestamp and raise its
	completion bit.

Signed-off-by: Dani Liberman <dliberman@habana.ai>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>