HW PWM sanity checks for SPINDLE_LASER_FREQUENCY (#18947)

Marlin/src/HAL/LPC1768/fast_pwm.cpp

@@ -35,5 +35,5 @@ void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255
   LPC176x::pwm_write_ratio(pin, invert ? 1.0f - (float)v / v_size : (float)v / v_size);
 }
 
-#endif // FAST_PWM_FAN || SPINDLE_LASER_PWM
+#endif // NEEDS_HARDWARE_PWM
 #endif // TARGET_LPC1768

Marlin/src/HAL/LPC1768/inc/SanityCheck.h

@@ -59,6 +59,10 @@
  */
 static_assert(!(NUM_SERVOS && ENABLED(FAST_PWM_FAN)), "BLTOUCH and Servos are incompatible with FAST_PWM_FAN on LPC176x boards.");
 
+#if SPINDLE_LASER_FREQUENCY
+  static_assert(!NUM_SERVOS, "BLTOUCH and Servos are incompatible with SPINDLE_LASER_FREQUENCY on LPC176x boards.");
+#endif
+
 /**
  * Test LPC176x-specific configuration values for errors at compile-time.
  */