[yocto] using and auditing kernel config fragments

[Autif Khan]

>> For some reason which I cannot work out, the rt2800usb options are
>> removed (rather then disabled) from the yocto kernel config, i.e., if I
>> run 'bitbake -c menuconfig linux-yocto', there is very little under
>> Drivers->Net->WLAN. If I run menuconfig in the devshell, there are lots
>> more WLAN drivers available, including the rt2800.
>
> Under Device Drivers -> Network device support -> Wireless LAN, You
> have to enable Ralink driver support to see the options for
> CONFIG_RT2800USB
>
> It is not under Device Drivers -> Network device support -> Wireless LAN
>
> It is under Device Drivers -> Network device support -> Wireless LAN
> -> Ralink driver support

I forgot to mention - Under Networking Support -> Wireless, you need
to enable cfg80211 AND msc80211 (Generic IEEE 802.11 Netowrking Stack)

Then the Ralink driver support shows up under Wireless LAN