expo: Adjust how menu items are highlighted

At present when the user moves to a new menu item, the menu code
handles this immediately. This means it is not possible to use an expo
action to effect the same change.

Update this so that EXPOACT_POINT_ITEM is handled in cedit_do_action().

Expand the test to cover this.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/boot/expo.c b/test/boot/expo.c
index 616071e..b32a459 100644
--- a/test/boot/expo.c
+++ b/test/boot/expo.c
@@ -589,6 +589,8 @@
 	ut_assertok(expo_render(exp));
 
 	ut_asserteq(0, scn->highlight_id);
+	ut_assertok(scene_arrange(scn));
+	ut_asserteq(0, scn->highlight_id);
 
 	/* move down */
 	ut_assertok(expo_send_key(exp, BKEY_DOWN));
@@ -599,6 +601,7 @@
 	ut_asserteq(ITEM2, act.select.id);
 	ut_assertok(scene_menu_select_item(scn, OBJ_MENU, act.select.id));
 	ut_asserteq(ITEM2, scene_menu_get_cur_item(scn, OBJ_MENU));
+	ut_assertok(scene_arrange(scn));
 	ut_assertok(expo_render(exp));
 
 	/* make sure only the preview for the second item is shown */
@@ -639,6 +642,7 @@
 
 	ut_asserteq(EXPOACT_POINT_ITEM, act.type);
 	ut_asserteq(ITEM1, act.select.id);
+	ut_assertok(scene_menu_select_item(scn, OBJ_MENU, act.select.id));
 
 	ut_assertok(expo_render(exp));
 	ut_assert_nextline("U-Boot    :    Boot Menu");