Merge remote-tracking branch 'remotes/kraxel/tags/modules-20201015-pull-request'...

modules: misc fixes & tweaks.
modules: build spice chardevs as module.

# gpg: Signature made Thu 15 Oct 2020 13:53:03 BST
# gpg:                using RSA key 4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/modules-20201015-pull-request:
  chardev/spice: build spice chardevs as module
  meson: add spice dependency to core spice source files.
  meson: add spice_headers dependency.
  chardev/spice: simplify chardev setup
  chardev/spice: make qemu_chr_open_spice_port static
  ui/spice-app: don't use qemu_chr_open_spice_port directly
  modules: update qom object module comment
  module: silence errors for module_load_qom_all().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>