Fix min max range for ScanCapability.Impact

[duttajnu]

Device.WiFi.DataElements.Network.Device.{i}.Radio.{i}.ScanCapability.Impact description and range does not match, value 0 does not defined in description and value 4 does not meets the range criterion.

<parameter name="Impact" access="readOnly">
<description>
Scan Impact of using this radio to perform a scan. : 1: No impact, : 2: Reduced number of spatial streams, : 3: Time slicing impairment, : 4: Radio unavailable for >= 2 seconds.
</description>
<syntax>
<unsignedInt>
<range maxInclusive="3"/>
</unsignedInt>
</syntax>
</parameter>