pang12: proprietary BIOS doesn't have FlexiCharger support

[leviport]

https://support.system76.com/articles/laptop-battery-thresholds#configuring-flexicharger-proprietary-firmware

[ahoneybun]

Does the pang13 not support it either?

[leviport]

It does not

[ahoneybun]

I have a PR to add a note about both models then:

#1167

[ahoneybun]

Updated the article so closing.

https://support.system76.com/articles/laptop-battery-thresholds#configuring-flexicharger-proprietary-firmware