habanalabs/gaudi2: change memory scrub mechanism

habanalabs/gaudi2: change memory scrub mechanism

Currently the scrubbing mechanism used the EDMA engines by directly
setting the engine core registers to scrub a chunk of memory.
Due to a sporadic failure with this mechanism, it was decided to
initiate the engines via its QMAN using LIN-DMA packets.

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