detect: Reporting ethernet firmware version

This patch comes from a real case where 3 nodes were supposed to be the
same but not. One of the boards didn't had the same nic firmware at all.

This patch introduce the firmware version reporting of it.

A typical output looks like :

('network', 'enp0s25', 'vendor', 'Intel Corporation'),
('network', 'enp0s25', 'product', '82579LM Gigabit Network Connection'),
('network', 'enp0s25', 'firmware', '0.13-3'),