Add disable_e_steppers function

Marlin/Marlin.h

@@ -223,6 +223,7 @@ void manage_inactivity(bool ignore_stepper_queue = false);
 #define _AXIS(AXIS) AXIS ##_AXIS
 
 void enable_all_steppers();
+void disable_e_steppers();
 void disable_all_steppers();
 
 void FlushSerialRequestResend();