MAINTAINERS: Update MELLANOX MLX5 core VPI driver maintainers

Add myself as a maintainer for mlx5 core driver as well.
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

MAINTAINERS

@@ -8053,6 +8053,7 @@ F:	drivers/infiniband/hw/mlx4/
 F:	include/linux/mlx4/
 
 MELLANOX MLX5 core VPI driver
+M:	Saeed Mahameed <saeedm@mellanox.com>
 M:	Matan Barak <matanb@mellanox.com>
 M:	Leon Romanovsky <leonro@mellanox.com>
 L:	netdev@vger.kernel.org