implement display power (#21731)

* implement display power

* FB_BLANK_POWERDOWN

Co-authored-by: Adeeb Shihadeh <adeebshihadeh@gmail.com>

selfdrive/hardware/tici/hardware.h

@@ -25,7 +25,13 @@ public:
       brightness_control.close();
     }
   };
-  static void set_display_power(bool on) {};
+  static void set_display_power(bool on) {
+    std::ofstream bl_power_control("/sys/class/backlight/panel0-backlight/bl_power");
+    if (bl_power_control.is_open()) {
+      bl_power_control << (on ? "0" : "4") << "\n";
+      bl_power_control.close();
+    }
+  };
 
   static bool get_ssh_enabled() { return Params().getBool("SshEnabled"); };
   static void set_ssh_enabled(bool enabled) { Params().putBool("SshEnabled", enabled); };