habanalabs: fix kernel OOPs related to staged cs

In case of single staged cs with both first/last indications
set, we reach a scenario where in cs_release function flow
we don't cancel the TDR work before freeing the cs memory,
this lead to kernel OOPs since when the timer expires
the work pointer will be freed already.
In addition treat wait encaps cs "not found" handle
as "OK" for the user in order to keep the user interface
for both legacy and encpas signal/wait features the same.

Signed-off-by: farah kassabri <fkassabri@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>