drm/panel-edp: Don't re-read the EDID every time we power off the panel

The simple-panel driver is for panels that are not hot-pluggable at
runtime. Let's keep our cached EDID around until driver unload.
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.v5.14.Ib810fb3bebd0bd6763e4609e1a6764d06064081e@changeid

drivers/gpu/drm/panel/panel-edp.c

@@ -362,9 +362,6 @@ static int panel_edp_suspend(struct device *dev)
 	regulator_disable(p->supply);
 	p->unprepared_time = ktime_get();
 
-	kfree(p->edid);
-	p->edid = NULL;
-
 	return 0;
 }
 
@@ -758,6 +755,9 @@ static int panel_edp_remove(struct device *dev)
 	if (panel->ddc && (!panel->aux || panel->ddc != &panel->aux->ddc))
 		put_device(&panel->ddc->dev);
 
+	kfree(panel->edid);
+	panel->edid = NULL;
+
 	return 0;
 }