net/mlx5e: Add offloading of E-Switch TC pedit (header re-write) actions

This includes calling the parsing code that translates from pedit
speak to the HW API, allocation (deallocation) of a modify header
context and setting the modify header id associated with this
context to the FTE of that flow.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>