Move "1000baseT" from IFM_SUBTYPE_ETHERNET_DESCRIPTIONS to
IFM_SUBTYPE_ETHERNET_ALIASES: there is already "1000baseTX" in
IFM_SUBTYPE_ETHERNET_DESCRIPTIONS. This doesn't change ifconfig
behaviour.
PR: 45793 (maybe)
Approved by: rwatson (mentor)
MFC after: 1 month