params: add script to parse timer_config.cpp for timer group info

This allows to generate pwm params in the form of:
module_name: PWM Output
actuator_output:
  output_groups:
    - generator: pwm
      param_prefix: PWM_FMU
      channel_labels: ['PWM Main', 'PWM Capture']
      standard_params:
        disarmed: { min: 800, max: 2200, default: 900 }
        min: { min: 800, max: 1400, default: 1000 }
        max: { min: 1600, max: 2200, default: 2000 }
        failsafe: { min: 800, max: 2200 }
      extra_function_groups: [ pwm_fmu ]
      pwm_timer_param:
        description:
            short: Output Protocol Configuration for ${label}
            long: |
                Select which Output Protocol to use for outputs ${label}.

                Custom PWM rates can be used by directly setting any value >0.
        type: enum
        default: 400
        values:
            -5: DShot150
            -4: DShot300
            -3: DShot600
            -2: DShot1200
            -1: OneShot
            50: PWM50
            100: PWM100
            200: PWM200
            400: PWM400
        reboot_required: true

src/lib/parameters/CMakeLists.txt

@@ -88,6 +88,7 @@ add_custom_command(OUTPUT ${generated_serial_params_file} ${generated_module_par
 	COMMAND ${PYTHON_EXECUTABLE} ${PX4_SOURCE_DIR}/Tools/module_config/generate_params.py
 		--params-file ${generated_module_params_file}
 		${added_arguments}
+		--timer-config ${PX4_BOARD_DIR}/src/timer_config.cpp
 		--config-files ${module_config_files} #--verbose
 	DEPENDS
 		${module_config_files}