puzzles: disable software poweroff in all puzzles

We have a couple games like Untangle and mouse-mode games in which the
software poweroff is very annoying.

Change-Id: I554b89aecf8c7cc20c6c7f305be1b8807dc9283b

apps/plugins/puzzles/rockbox.c

@@ -3012,6 +3012,10 @@ static void shutdown_tlsf(void)
 
 static void exit_handler(void)
 {
+#ifdef HAVE_SW_POWEROFF
+    sw_poweroff_restore();
+#endif
+
     unload_fonts();
     shutdown_tlsf();
 
@@ -3270,8 +3274,11 @@ static void puzzles_main(void)
 {
     rb_atexit(exit_handler);
 
-    init_default_settings();
+#ifdef HAVE_SW_POWEROFF
+    sw_poweroff_disable();
+#endif
 
+    init_default_settings();
     init_fonttab();
 
     load_success = load_game();