Cutter Power in percent format (MarlinFirmware#20410)

Co-authored-by: Scott Lahteine <thinkyhead@users.noreply.github.com>
Co-authored-by: Jason Smith <jason.inet@gmail.com>
Co-authored-by: Luu Lac <45380455+shitcreek@users.noreply.github.com>

buildroot/tests/BIGTREE_SKR_PRO-tests

@@ -37,5 +37,14 @@ opt_add SPINDLE_LASER_PWM_PIN HEATER_1_PIN
 opt_add SPINDLE_LASER_ENA_PIN HEATER_2_PIN
 exec_test $1 $2 "Laser, LCD, PERCENT power unit" "$3"
 
+restore_configs
+opt_set MOTHERBOARD BOARD_BTT_SKR_PRO_V1_1
+opt_set SERIAL_PORT -1
+opt_enable LASER_FEATURE REPRAP_DISCOUNT_SMART_CONTROLLER
+opt_set CUTTER_POWER_UNIT PERCENT
+opt_add SPINDLE_LASER_PWM_PIN HEATER_1_PIN
+opt_add SPINDLE_LASER_ENA_PIN HEATER_2_PIN
+exec_test $1 $2 "Laser, LCD, PERCENT power unit" "$3"
+
 # clean up
 restore_configs