habanalabs: Replace dma-fence mechanism with completions

habanalabs driver uses dma-fence mechanism for synchronization.
dma-fence mechanism was designed solely for GPUs, hence we purpose
a simpler mechanism based on completions to replace current
dma-fence objects.

Signed-off-by: Ofir Bitton <obitton@habana.ai>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>