Add missing file (#13754)

Marlin/src/HAL/shared/HAL_ST7920.h

@@ -0,0 +1,36 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2019 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#pragma once
+
+/**
+ * HAL/HAL_ST7920.h
+ * For the HALs that provide direct access to the ST7920 display
+ * (bypassing U8G), it will allow the LIGHTWEIGHT_UI to operate.
+ */
+
+#if HAS_GRAPHICAL_LCD && ENABLED(LIGHTWEIGHT_UI)
+  void ST7920_cs();
+  void ST7920_ncs();
+  void ST7920_set_cmd();
+  void ST7920_set_dat();
+  void ST7920_write_byte(const uint8_t data);
+#endif