Configuration.m: Set PID_INTEGRAL_DRIVE_MAX from PID_MAX from BANG_MAX.

Current defaults are all 255.  If it makes sense to reduce them, they should come down together, and
be in a  PID_INTEGRAL_DRIVE_MAX <= PID_MAX <- BANG_MAX relationship.

Marlin/Configuration.h

 // Comment the following line to disable PID and enable bang-bang.
 #define PIDTEMP
 #define BANG_MAX 255 // limits current to nozzle while in bang-bang mode; 255=full current
-#define PID_MAX 255 // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
+#define PID_MAX BANG_MAX // limits current to nozzle while PID is active (see PID_FUNCTIONAL_RANGE below); 255=full current
 #ifdef PIDTEMP
   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
   #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                   // is more then PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
-  #define PID_INTEGRAL_DRIVE_MAX 255  //limit for the integral term
+  #define PID_INTEGRAL_DRIVE_MAX PID_MAX  //limit for the integral term
   #define K1 0.95 //smoothing factor within the PID
   #define PID_dT ((OVERSAMPLENR * 10.0)/(F_CPU / 64.0 / 256.0)) //sampling period of the temperature routine