net/ena: update version to 2.0.0

net/ena: update version to 2.0.0

The ENAv2 is introducing many new features, mainly the LLQ feature
(Low Latency Queue) which allows the device to process packets faster
and as a result, the latency is noticeably lower.

The second major feature is configurable depth of hw queues where Rx
and Tx can be reconfigured independently and maximum depth of Rx queue
is 8k.

The release also includes many bug fixes and minor new features, like
improved statistics counters and extended statistics.

Driver is still compatible with ENAv1 device.

Signed-off-by: Michal Krawczyk <mk@semihalf.com>