bhyve nvme: Add missing Admin opcodes

Don't treat unsupported Admin commands as Invalid Opcode. Instead return
the proper Invalid Field in Command.

Fixes UNH IOL test 1.17.2

Reviewed by: imp, allanjude
Tested by: jason@tubnor.net
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D33569