The "isapc" machine can also be run without VGA card, so there
is no need for a hard requirement with a "select" here - "imply"
is enough.

Message-Id: <20230512124033.502654-2-thuth@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>