drm: drop _mode_ from update_edit_property()

Just makes it longer, and for most things in drm_connector.[hc] we
just use the drm_connector_ prefix. Done with sed + a bit of manual
fixup for the indenting.

Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180709084016.23750-6-daniel.vetter@ffwll.ch