hyperv: Identify Hyper-V features and recommends properly

Features bits will be used to detect devices, e.g. timers, which
do not have corresponding event channels.

Submitted by: Jun Su <junsu microsoft com>
Reviewed by: sephe, Dexuan Cui <decui microsoft com>
Rearranged by: sephe
MFC after: 1 week
Sponsored by: Microsoft OSTC