drm: drop _mode_ from remaining connector functions

Since there's very few callers of these I've decided to do them all in
one patch. With this the unecessarily long drm_mode_connector_ prefix
is gone from the codebase! The only exception being struct
drm_mode_connector_set_property, which is part of the uapi so can't be
renamed.

Again done with sed+some manual fixups for indent issues.

Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180709084016.23750-8-daniel.vetter@ffwll.ch