Refine EEPROM types / flags (#17772)

Marlin/src/HAL/shared/eeprom_if.h

@@ -0,0 +1,30 @@
+/**
+ * Marlin 3D Printer Firmware
+ *
+ * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ * Copyright (c) 2016 Bob Cousins bobcousins42@googlemail.com
+ * Copyright (c) 2015-2016 Nico Tonnhofer wurstnase.reprap@gmail.com
+ *
+ * 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
+
+//
+// EEPROM
+//
+void eeprom_write_byte(uint8_t *pos, unsigned char value);
+uint8_t eeprom_read_byte(uint8_t *pos);
+void eeprom_read_block(void *__dst, const void *__src, size_t __n);
+void eeprom_update_block(const void *__src, void *__dst, size_t __n);