bhyve nvme: Fix Set Features

Be more conservative and only support the Features mandatory for an I/O
Controller.

Avoids a "hang" in UNH test 1.2.10 associated with Predictable Latency
Mode Configuration and Host Behavior Support features.

Tested by: jason@tubnor.net
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D33571