Move this static inline function to processor.h, so that it can be
used in individual tests, as needed.

Opportunistically replace the bare 'unsigned' with 'unsigned int.'
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220115052431.447232-5-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>