Add virtual PMD which communicates with COMBO cards through sze2
layer using libsze2 library.
Since link_speed is uint16_t, there can not be used number for 100G
speed, therefore link_speed is set to ETH_LINK_SPEED_10G until the
type of link_speed is solved.
Signed-off-by: Matej Vido <matejvido@gmail.com>
