MK2_MULTIPLEXER dependency

platformio.ini

   -<src/feature/probe_temp_comp.cpp>
   -<src/feature/repeat.cpp>
   -<src/feature/runout.cpp> -<src/gcode/feature/runout>
+  -<src/feature/snmm.cpp>
   -<src/feature/solenoid.cpp> -<src/gcode/control/M380_M381.cpp>
   -<src/feature/spindle_laser.cpp> -<src/gcode/control/M3-M5.cpp>
   -<src/feature/tmc_util.cpp> -<src/module/stepper/trinamic.cpp>
 PROBE_TEMP_COMPENSATION = src_filter=+<src/feature/probe_temp_comp.cpp> +<src/gcode/calibrate/G76_M192_M871.cpp>
 HAS_FILAMENT_SENSOR     = src_filter=+<src/feature/runout.cpp> +<src/gcode/feature/runout>
 (EXT|MANUAL)_SOLENOID.* = src_filter=+<src/feature/solenoid.cpp> +<src/gcode/control/M380_M381.cpp>
+MK2_MULTIPLEXER         = src_filter=+<src/feature/snmm.cpp>
 HAS_CUTTER              = src_filter=+<src/feature/spindle_laser.cpp> +<src/gcode/control/M3-M5.cpp>
 EXPERIMENTAL_I2CBUS     = src_filter=+<src/feature/twibus.cpp> +<src/gcode/feature/i2c>
 MECHANICAL_GANTRY_CAL.+ = src_filter=+<src/gcode/calibrate/G34.cpp>