Update FYSETC S6 pins/variants (#17056)

Marlin/src/pins/stm32/pins_FYSETC_S6.h

 // EEPROM Emulation
 //
 #define FLASH_EEPROM_EMULATION
+#if ENABLED(FLASH_EEPROM_EMULATION)
+  #define FLASH_EEPROM_LEVELING
+#endif
 //#define SRAM_EEPROM_EMULATION
 //#define I2C_EEPROM
 #ifdef I2C_EEPROM
 
 //
 // Filament Sensor
+// share with X_MAX_PIN
 //
 #ifndef FIL_RUNOUT_PIN
   #define FIL_RUNOUT_PIN   PA1

buildroot/share/PlatformIO/variants/FYSETC_S6/variant.h

 #define NUM_ANALOG_FIRST        80
 
 // PWM resolution
-#define PWM_RESOLUTION          8
+#define PWM_RESOLUTION          12
 #define PWM_FREQUENCY           20000 // >= 20 Khz => inaudible noise for fans
 #define PWM_MAX_DUTY_CYCLE      255