There is no upstream driver and no current attempt to author an upstreamable driver that I can see.
This appears to be the most widely used driver source that I can see: https://github.com/fifteenhex/xradio and this probably makes it the 'least worst' to use (the repo README is honest). This chipset has quite a reputation for being rubbish once you start looking-for and finding information on it.
LE has zero interest in adding out-of-tree drivers with no upstream plan to the buildsystem, but a self-built image can probably be done. I spotted some notes here: RE: How helpful will this be to getting LibreELEC on allwinner android boxes? and the zip file posted there contains some examples of the kernel device-tree changes that would be needed alongside the kernel driver itself. There are other threads that mention XR819 but they look to be mostly users asking for drivers and being told that it's not supported.
Unless you like the development challenge (with the likelihood of a poor experience outcome even if successful) I'd probably just get myself a USB wifi dongle or a USB-powered Ethernet/WiFi bridge dongle and not go down the self-built image route.
If you do, the Realtek out-of-tree drivers found in older LE images (LE11 for example) are probably a good starting point for cribbing the format for a simple buildsystem package that compiles the driver.