net/ena/base: make IO memzone unique per port

net/ena/base: make IO memzone unique per port

Originally, the ena_com memzone counter was shared by ports, which
caused the memzones to be harder to identify and could potentially
lead to race and because of that the counter had to be atomic.

This atomic counter was global variable and it couldn't work in the
multiprocess implementation.

The memzone is now being identified by the local to port memzone counter
and the port ID - both of those information can be found in the shared
data, so it can be probed easily.

Signed-off-by: Michal Krawczyk <mk@semihalf.com>
Reviewed-by: Dawid Gorecki <dgr@semihalf.com>
Reviewed-by: Shai Brandes <shaibran@amazon.com>