net/mlx5e: Refactor eswitch attr flags to just attr flags

The flags are flow attrs and not esw specific attr flags.
Refactor to remove the esw prefix and move from eswitch.h
to en_tc.h where struct mlx5_flow_attr exists.

Signed-off-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Oz Shlomo <ozsh@nvidia.com>
Reviewed-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>