systemd: update to systemd-204

Signed-off-by: Stephan Raue <stephan@openelec.tv>
systemd: enable LTO and linker-plugin support

Signed-off-by: Stephan Raue <stephan@openelec.tv>
lockdev: build as static library

Signed-off-by: Stephan Raue <stephan@openelec.tv>