Fix 5 mixing steppers

Marlin/src/Marlin.h

   /**
    * Mixing steppers synchronize their enable (and direction) together
    */
-  #if MIXING_STEPPERS > 3
+  #if MIXING_STEPPERS > 4
+    #define  enable_E0() { E0_ENABLE_WRITE( E_ENABLE_ON); E1_ENABLE_WRITE( E_ENABLE_ON); E2_ENABLE_WRITE( E_ENABLE_ON); E3_ENABLE_WRITE( E_ENABLE_ON); E4_ENABLE_WRITE( E_ENABLE_ON); }
+    #define disable_E0() { E0_ENABLE_WRITE(!E_ENABLE_ON); E1_ENABLE_WRITE(!E_ENABLE_ON); E2_ENABLE_WRITE(!E_ENABLE_ON); E3_ENABLE_WRITE(!E_ENABLE_ON); E4_ENABLE_WRITE(!E_ENABLE_ON); }
+  #elif MIXING_STEPPERS > 3
     #define  enable_E0() { E0_ENABLE_WRITE( E_ENABLE_ON); E1_ENABLE_WRITE( E_ENABLE_ON); E2_ENABLE_WRITE( E_ENABLE_ON); E3_ENABLE_WRITE( E_ENABLE_ON); }
     #define disable_E0() { E0_ENABLE_WRITE(!E_ENABLE_ON); E1_ENABLE_WRITE(!E_ENABLE_ON); E2_ENABLE_WRITE(!E_ENABLE_ON); E3_ENABLE_WRITE(!E_ENABLE_ON); }
   #elif MIXING_STEPPERS > 2

Marlin/src/feature/power.cpp

     if (controllerFanSpeed > 0) return true;
   #endif
 
+  // If any of the drivers or the bed are enabled...
   if (X_ENABLE_READ == X_ENABLE_ON || Y_ENABLE_READ == Y_ENABLE_ON || Z_ENABLE_READ == Z_ENABLE_ON
     #if HAS_HEATED_BED
       || thermalManager.soft_pwm_amount_bed > 0
     #endif
-      || E0_ENABLE_READ == E_ENABLE_ON // If any of the drivers are enabled...
+      #if HAS_X2_ENABLE
+        || X2_ENABLE_READ == X_ENABLE_ON
+      #endif
+      #if HAS_Y2_ENABLE
+        || Y2_ENABLE_READ == Y_ENABLE_ON
+      #endif
+      #if HAS_Z2_ENABLE
+        || Z2_ENABLE_READ == Z_ENABLE_ON
+      #endif
+      || E0_ENABLE_READ == E_ENABLE_ON
       #if E_STEPPERS > 1
         || E1_ENABLE_READ == E_ENABLE_ON
-        #if HAS_X2_ENABLE
-          || X2_ENABLE_READ == X_ENABLE_ON
-        #endif
         #if E_STEPPERS > 2
             || E2_ENABLE_READ == E_ENABLE_ON
           #if E_STEPPERS > 3
               || E3_ENABLE_READ == E_ENABLE_ON
+            #if E_STEPPERS > 4
+                || E4_ENABLE_READ == E_ENABLE_ON
+            #endif
           #endif
         #endif
       #endif