net/mlx5e: TC, Reject rules with drop and modify hdr action

This kind of action is not supported by firmware and generates a
syndrome.

kernel: mlx5_core 0000:08:00.0: mlx5_cmd_check:777:(pid 102063): SET_FLOW_TABLE_ENTRY(0x936) op_mod(0x0) failed, status bad parameter(0x3), syndrome (0x8708c3)

Fixes: d7e75a32

 ("net/mlx5e: Add offloading of E-Switch TC pedit (header re-write) actions")
Signed-off-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Reviewed-by: Oz Shlomo <ozsh@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>