Revert "qemu: command: add support for acpi-bridge-hotplug feature"

Revert "qemu: command: add support for acpi-bridge-hotplug feature"

This reverts commit bef0f0d8be6baa1d9359be208b53d6b8a37ddc95.

Conflicts:
 tests/qemuxml2argvdata/q35-acpi-hotplug-bridge-disable.args

  * this file had been renamed from its original, then renamed back,
    which understandably confused git. It's being completely removed
    here anyway, so the contents don't matter.

 tests/qemuxml2argvtest.c

  * change in context around removed chunk

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Ani Sinha <ani@anisinha.ca>