LinuxKPI; add more defintions to netdevice.h

Add new enums to netdevice.h (including one which is referenced but
no value of it is used in a driver so we have to add a "dummy" value
to avoid an empty enum).

Sponsored by: The FreeBSD Foundation

(cherry picked from commit 6ed447b51a9d6cf22aae2dfba6efce3922ae6d57)