accel/habanalabs: remove redundant TODOs

As mmu refactor and nic resume are not relevant anymore, remove
their TODO comments.

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