Give all temp arrays 4 indices

Marlin/temperature.cpp

@@ -53,10 +53,10 @@
 //============================= public variables ============================
 //===========================================================================
 
-int target_temperature[EXTRUDERS] = { 0 };
+int target_temperature[4] = { 0 };
 int target_temperature_bed = 0;
-int current_temperature_raw[EXTRUDERS] = { 0 };
-float current_temperature[EXTRUDERS] = { 0.0 };
+int current_temperature_raw[4] = { 0 };
+float current_temperature[4] = { 0.0 };
 int current_temperature_bed_raw = 0;
 float current_temperature_bed = 0.0;
 #ifdef TEMP_SENSOR_1_AS_REDUNDANT