Bhyve: Detect Extended Destination ID support

Bhyve advertises support for the Extended Destination ID standard via
bit 0 (aka CPUID_BHYVE_FEAT_EXT_DEST_ID) of the value returned in the
EAX register when Bhyve features are queried via CPUID.

MFC after: 3 weeks
Sponsored by: Amazon
Differential Revision: https://reviews.freebsd.org/D55431