common/sfc_efx/base: support MAC address edit actions in MAE

In a tunnel packet, these actions affect the inner header if
action DECAP is set; otherwise, they affect the outer header.

Adding these actions is done in two steps: add the action to
the action mask and indicate the MAC address entry ID to use.
This allows the user to check the order of actions first and
allocate resources when time comes to enable the action rule.

Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>
Reviewed-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
Reviewed-by: Andy Moreton <amoreton@xilinx.com>