habanalabs: avoid soft lockup bug upon mapping error

Add a little sleep between page unmappings in case mapping of
large number of host pages failed, in order to
avoid soft lockup bug during the rollback.

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