habanalabs: add debugfs node for configuring CS timeout

Command submission timeout is currently determined during driver
loading time. As some environments requires this timeout to be
modified in runtime, we introduce a new debugfs node that controls
the timeout value without the need to reload the driver.

Signed-off-by: Ofir Bitton <obitton@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>