net/ena: remove unused enumeration

net/ena: remove unused enumeration

The enumeration seems to be leftover from porting the Linux driver to
the DPDK. It was used nowhere and refers to the ethtool which is not
present in the DPDK.

Fixes: 372c1af5ed8f ("net/ena: add dedicated memory area for extra device info")
Cc: stable@dpdk.org
Signed-off-by: Michal Krawczyk <mk@semihalf.com>
Reviewed-by: Artur Rojek <ar@semihalf.com>
Reviewed-by: Dawid Gorecki <dgr@semihalf.com>
Reviewed-by: Igor Chauskin <igorch@amazon.com>
Reviewed-by: Shai Brandes <shaibran@amazon.com>