system: update checkout.

Submodule system f33acce..8d6e478:
  > framework: update checkout.
  > system/essential/verbatim-files: udev/rules.d: add 60-elevator.conf: default elevators for {,non}rotational devices.
  > system/essential/verbatim-files: issue, locale.conf: ditch, site-specific.
  > system/essential/verbatim-files: udev/rules.d/70-pm-usb-logitech.rules: ditch, site-specific.
  > configs: ditch.