[c-nsp] Hw field in 7600 show mod

[John Neiberger]

I'm trying to compare two 7600s. We're seeing an odd issue on one, but
not the other. They both have SUP720-3BXLs on them, but the Hw field
on the first one is 5.3, while the second one is 5.7. We're seeing
this issue on the router with the 5.3 version, but we're not seeing it
on the 5.7 router. This is a multicast issue that we thought we had
figured out, but then we realized that if we were right then it should
be affecting both boxes.

Any idea what the Hw field is for? Does that indicate an earlier
version of that blade?