[c-nsp] SFP & GBIC module compatibility

[Anton Kapela]

> IOS (tm) s72033_rp Software (s72033_rp-PK9SV-M), Version 
> 12.2(17d)SXB11a, RELEASE SOFTWARE (fc1)

Is 12.2(18) _that_ scary? (18)SXE or SXF for the win.

-Tk