doc: update mlx PMD release notes
doc: update mlx PMD release notes

Signed-off-by: Shahaf Shuler <59427d49da6f2b944fbf4cb5ee70ef3ac25f744f@mellanox.com>
Acked-by: Nelio Laranjeiro <2f8dd9032d5b85ca4b53dec8ce664eb6998836be@6wind.com>
Acked-by: Adrien Mazarguil <9d39ea493ca46c560334f650ac5d4b5ffbcb5cf0@6wind.com>

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