net: ena: Remove module param and change message severity

Remove the module param 'debug' which allows to specify the message
level of the driver. This value can be specified using ethtool command.
Also reduce the message level of LLQ support to be a warning since it is
not an indication of an error.

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>