habanalabs: debugfs access to user mapped host addresses

In order to have a better debuggability we allow debugfs access
to user mmu mapped host memory. Non-user host memory access will be
rejected.

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