x86: add modern network modules to Generic target

x86: add modern network modules to Generic target

Many Atom-based embedded/industrial x86 boards can't run 64bit operating
systems due to either processor or board firmware limitations, but they
have modern interfaces (PCIe) or have modern Intel gigabit controllers
onboard.  With the current default package selection for x86 Generic
target their network won't work.

Add the modern gigabit network modules needed or most likely going to be
used as add-in cards, similar to what is the list on x86_64 target.

Signed-off-by: Alberto Bursi <alberto.bursi@outlook.it>
[fixed whitespace issue]
Signed-off-by: Petr Štetiar <ynezz@true.cz>