net/mlx5e: Add helper functions for reporter's basics

Introduce helper functions for create and destroy reporters and update
channels. In the following patch, rx reporter is added and it will use
these helpers too.

Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>