net/mlx5e: TC, Move pedit_headers_action to parse_attr

Move pedit_headers_action from flow parse_state to flow parse_attr.
In a follow up commit we are going to have multiple attr per flow
and pedit_headers_action are unique per attr.

Signed-off-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Oz Shlomo <ozsh@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>