habanalabs: add topic to memory manager buffer

Currently, buffers from multiple flows pass through the same infra.
This way, in logs, we are unable to distinguish between buffers that
came from separate flows.
To address this problem, add a "topic" to buffer behavior
descriptor - a string identifier that will be used to identify in logs
the flow this buffer relates to.

Signed-off-by: Yuri Nudelman <ynudelman@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>