habanalabs: move dram scrub to free sequence

DRAM scrubbing can take time hence it adds to latency during allocation.
To minimize latency during initialization, scrubbing is moved to release
call.
In case scrubbing fails it means the device is in a bad state,
hence HARD reset is initiated.

Signed-off-by: Bharat Jauhari <bjauhari@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>