- Don't set MIIF_NOISOLATE so amphy(4) can be used in configurations
with multiple PHYs. There doesn't seem to be a problem with isolating
AM79c873 and workalikes per se nor in combination with the NICs they're
used with and amphy(4) was already adding IFM_NONE anyway.
- Use mii_phy_add_media() instead of mii_add_media() so the latter can
be eventually retired.
- Take advantage of mii_phy_setmedia().
- Fix a whitespace nit.
Obtained from: NetBSD dmphy(4) (except for the last item)
MFC after: 2 weeks