📝 Fix M201 typos (MarlinFirmware#26854)

Author: Sophist-UK

Marlin/Configuration_adv.h

@@ -1152,11 +1152,11 @@
  * XY Frequency limit
  * Reduce resonance by limiting the frequency of small zigzag infill moves.
  * See https://hydraraptor.blogspot.com/2010/12/frequency-limit.html
- * Use M201 F<freq> G<min%> to change limits at runtime.
+ * Use M201 F<freq> S<min%> to change limits at runtime.
  */
 //#define XY_FREQUENCY_LIMIT      10 // (Hz) Maximum frequency of small zigzag infill moves. Set with M201 F<hertz>.
 #ifdef XY_FREQUENCY_LIMIT
-  #define XY_FREQUENCY_MIN_PERCENT 5 // (%) Minimum FR percentage to apply. Set with M201 G<min%>.
+  #define XY_FREQUENCY_MIN_PERCENT 5 // (%) Minimum FR percentage to apply. Set with M201 S<min%>.
 #endif
 
 // Minimum planner junction speed. Sets the default minimum speed the planner plans for at the end