net: Add support for "promiscous mode" to Axxia FEMAC

commit 2148096a29a2c2f518b2a67a0c63aaf4b5a8d664 from
https://github.com/axxia/linux-yocto.git

 v5.10/standard/axxia-dev/base.

The FEMAC hardware is always in promiscous mode.  Previously, all
packets not intended for this host were dropped.  Add a parameter,
promiscuous_mode, to allow all packats, and support the hook that
requests changes to the promiscous state.

Signed-off-by: John Jacques <john.jacques@intel.com>
Signed-off-by: Liwei Song <liwei.song@windriver.com>