src: video: xml: Flatten is working

[joaoantoniocardoso]

Example:

<mavlinkcamera>
  <definition version="1">
    <model>H264 USB Camera: USB Camera</model>
    <vendor>Missing</vendor>
  </definition>
  <parameters>
    <parameter name="9963776" type="int64" default="0" v4l_id="9963776" step="1" max="64" min="-64">
      <description>Brightness</description>
    </parameter>
    <parameter name="9963777" type="int64" default="32" v4l_id="9963777" step="1" max="64" min="0">
      <description>Contrast</description>
    </parameter>
    <parameter name="9963778" type="int64" default="56" v4l_id="9963778" step="1" max="128" min="0">
      <description>Saturation</description>
    </parameter>
    <parameter name="9963779" type="int64" default="0" v4l_id="9963779" step="1" max="40" min="-40">
      <description>Hue</description>
    </parameter>
    <parameter name="9963788" type="bool" default="1" v4l_id="9963788">
      <description>White Balance, Automatic</description>
    </parameter>
    <parameter name="9963792" type="int64" default="100" v4l_id="9963792" step="1" max="500" min="72">
      <description>Gamma</description>
    </parameter>
    <parameter name="9963795" type="int64" default="0" v4l_id="9963795" step="1" max="100" min="0">
      <description>Gain</description>
    </parameter>
    <parameter name="9963800" type="int32" default="1" v4l_id="9963800">
      <description>Power Line Frequency</description>
      <options>
        <option name="Disabled" value="0"/>
        <option name="50 Hz" value="1"/>
        <option name="60 Hz" value="2"/>
      </options>
    </parameter>
    <parameter name="9963802" type="int64" default="4600" v4l_id="9963802" step="1" max="6500" min="2800">
      <description>White Balance Temperature</description>
    </parameter>
    <parameter name="9963803" type="int64" default="3" v4l_id="9963803" step="1" max="6" min="0">
      <description>Sharpness</description>
    </parameter>
    <parameter name="9963804" type="int64" default="1" v4l_id="9963804" step="1" max="2" min="0">
      <description>Backlight Compensation</description>
    </parameter>
    <parameter name="10094849" type="int32" default="3" v4l_id="10094849">
      <description>Auto Exposure</description>
      <options>
        <option name="Manual Mode" value="1"/>
        <option name="Aperture Priority Mode" value="3"/>
      </options>
    </parameter>
    <parameter name="10094850" type="int64" default="156" v4l_id="10094850" step="1" max="5000" min="1">
      <description>Exposure Time, Absolute</description>
    </parameter>
    <parameter name="10094851" type="bool" default="0" v4l_id="10094851">
      <description>Exposure, Dynamic Framerate</description>
    </parameter>
  </parameters>
</mavlinkcamera>