FMC GA pins lack current-limiting resistors

LD signalled: There is a notable lack of current-limiting resistors on the FMC GA pins, as suggested in Observation 5.19 of the FMC spec.

Observation 5.23: The mezzanine module may want to put a current limiting resistor on GA[0] and GA[1] signals.

From FMC standard Approved July 2008 (Revised February 2010) https://cds.cern.ch/record/1172409/files/ANSI-VITA-57-1-Rev2010.pdf