Fix Lerdge K typos (#15273)

Marlin/src/core/boards.h

 #define BOARD_STEVAL                  4206  // STEVAL-3DP001V1 3D PRINTER BOARD
 #define BOARD_BIGTREE_SKR_PRO_V1_1    4207  // BigTreeTech SKR Pro v1.1 (STM32F407ZG)
 #define BOARD_BIGTREE_BTT002_V1_0     4208  // BigTreeTech BTT002 v1.0 (STM32F407VE)
-#define BOARD_LERDGE_K                4209  // Lerdge K (STM32F407VE)
+#define BOARD_LERDGE_K                4209  // Lerdge K (STM32F407ZG)
 #define BOARD_LERDGE_X                4210  // Lerdge X (STM32F407VE)
 
 //

Marlin/src/pins/lpc1768/pins_GMARSH_X6_REV1.h

 #define BOARD_INFO_NAME "GMARSH X6 REV1"
 
 // Ignore temp readings during develpment.
-//#define BOGUS_TEMPERATURE_FAILSAFE_OVERRIDE
+//#define BOGUS_TEMPERATURE_GRACE_PERIOD 2000
 
 //
 // Enable 12MHz clock output on P1.27 pin to sync TMC2208 chip clocks

Marlin/src/pins/stm32/pins_LERDGE_K.h

 /**
  * Marlin 3D Printer Firmware
- * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- *
- * Based on Sprinter and grbl.
- * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ * Copyright (c) 2019 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
  *
  * 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
 #define I2C_EEPROM
 
 // Ignore temp readings during develpment.
-//#define BOGUS_TEMPERATURE_FAILSAFE_OVERRIDE
+//#define BOGUS_TEMPERATURE_GRACE_PERIOD 2000
 
 //
 // Servos

Marlin/src/pins/stm32/pins_LERDGE_X.h

 /**
  * Marlin 3D Printer Firmware
- * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- *
- * Based on Sprinter and grbl.
- * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ * Copyright (c) 2019 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
  *
  * 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