Switch to legacy Wi-Fi

<!-- device manifest for MTK devices

     2017/9/9:  by:daniel_hk (https://github.com/danielhk) -->

<manifest version="1.0" type="device">

    <hal format="hidl">

        <name>android.hardware.audio</name>

    <hal format="hidl">

        <name>android.hardware.wifi</name>

        <transport>hwbinder</transport>

        <version>1.2</version>

        <version>1.0</version>

        <interface>

            <name>IWifi</name>

            <instance>default</instance>

            <instance>legacy/0</instance>

            <instance>legacy/1</instance>

        </interface>

    </hal>

    <hal format="hidl">