net/mlx5e: TC, Add tc prefix to attach/detach hdr functions

Currently there are confusing names for attach/detach functions.

mlx5e_attach_mod_hdr() vs mlx5e_mod_hdr_attach()
mlx5e_detach_mod_hdr() vs mlx5e_mod_hdr_detach()

Add tc prefix to the functions that are in en_tc.c to separate
from the functions in mod_hdr.c which has the mod_hdr prefix.

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