maintainers: update for ena
maintainers: update for ena

Remove Guy Tzalik as the driver's maintainer and add Shai Brandes who
will now be another maintainer of the ENA DPDK driver.

Signed-off-by: Michal Krawczyk <a91dcbb4df49d8bfe0a9930d7ff911a4292ca1f5@semihalf.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk