Merge remote-tracking branch 'kraxel/chardev.1' into staging

Merge remote-tracking branch 'kraxel/chardev.1' into staging

# By Gerd Hoffmann
# Via Gerd Hoffmann
* kraxel/chardev.1:
  chardev: add pty chardev support to chardev-add (qmp)
  chardev: add socket chardev support to chardev-add (qmp)
  chardev: add parallel chardev support to chardev-add (qmp)
  chardev: add serial chardev support to chardev-add (qmp)
  chardev: add file chardev support to chardev-add (qmp)
  chardev: add hmp hotplug commands
  chardev: add qmp hotplug commands, with null chardev support
  chardev: reduce chardev ifdef mess a bit
  chardev: fix QemuOpts lifecycle
  chardev: add error reporting for qemu_chr_new_from_opts