Read the appropriate registers for RTL8139, RTL8168 and E1000.
For NE2000 just assume 10mbit full duplex as there is no indicator
for it in the pure NE2000 spec. Mock values for loopback.
If we are in a shared interrupt handler, the called handlers might
indicate it was not their interrupt, so we should not increment the
call counter of these handlers.
These are pretty common on older LGA1366 & LGA1150 motherboards.
NOTE: Since the registers datasheets for all versions of the chip
besides versions 1 - 3 are still under NDAs i had to collect
several "magical vendor constants" from the *BSD driver and the
linux driver that i was not able to name verbosely, and as such
these are labeled with the comment "vendor magic values".
