Only 5 GHz on dual band wifi

[Pavel-Rychetsky]

HI,
at first - many thanks @devmfc for your work.

I've installed last release on Tesla X700 (https://eshop.tesla-electronics.eu/produkty/tesla-mediabox-x700-pro-4k-hdr-multimedialni-prehravac/ - only in Czech but technical info is readable well) with s905x2_generic_gigabit config.
Everything is working well instead of built-in dualband wifi which offer just 5 GHz channels (according hwinfo which reports only 5 GHz channels):

• I'm sure the 2.4 GHz could run because of previous use of builtin-in Android and also CoreELEC image
• the Wifi is based on rtl88x2bu driver, not know how to exactly identify chip
• I'd had idea the problem is based on regulatory database and switched it to "upstream" because of "debian" reports problems with certificates but problem presists
• now I've tried USB Wifi based on rtl8188 - just installed firmware bin file and everything is running well

Have you any idea how to unlock 2.4 GHz band on built-in dual band?