Add more BCM gigabit PHYs

[kbowling]

Summary

Gleaned from a public header file. 5402 and 5404 look like they may be
used on embedded devices. 5478 and 5488 are switch PHYs. 5754 change is just
to note a product alias.

Test Plan

I don't have any of these to test. They appear to all be part of
this family.