[2.0.x] Fix compile error (#11465)

Address #11463

Marlin/src/feature/Max7219_Debug_LEDs.cpp

   Max7219_PutByte(reg);          // specify register
   SIG_DELAY();
   Max7219_PutByte(data);         // put data
+  #ifndef CPU_32_BIT
     CRITICAL_SECTION_END;
+  #endif
 }
 
 #if ENABLED(MAX7219_NUMERIC)