[ofw] [ib-diag] sminfo: add support for WinOF

[Sean Hefty]

>What about to add files inttypes.h and unistd.h in winof tree? It could
>be wrapper similars to ibdiag_osd.h.

One advantage of using your approach is that the source files end up only
including those headers that it needs.  Moving everything into ibdiag_osd.h
means that the source files pick up other includes.  Anyway, just let me know
your preference, and I'll update the patches.

- Sean