Revert "drm/panel-simple: Add Samsung ATNA33XC20"

This reverts commit 4bfe6c8f.

This panel's power sequencing really can't be handled properly by
panel-simple because of the special sequencing needed for the EL_ON3
GPIO. The only way it was sorta working in the past was by trying to
jam that signal into the "enable-gpio", but that really wasn't a good
fit. We'll add a custom panel driver for this panel to do it right.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210730084534.v2.4.Id9f076ec5f35633f8ce931051af268a04c45c075@changeid