arm64: defconfig: Everyone who had PANEL_SIMPLE now gets PANEL_EDP

In the patch ("drm/panel-simple-edp: Split eDP panels out of
panel-simple") we split the PANEL_SIMPLE driver in 2. Let's enable the
new config.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.6.Ied5c4da3ea36f8c49343176eda342027b6f19586@changeid