Armbian is a build system in its core which, in this particular case, takes this source: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/?h=v4.19.75 add those patches https://github.com/armbian/build/tree/master/patch/kernel/sunxi-next + https://github.com/armbian/build/blob/master/lib/compilation-prepare.sh and use this config https://github.com/armbian/build/blob/master/config/kernel/linux-sunxi-next.config
Before compilation starts, sources are packed here: https://github.com/armbian/build/blob/master/lib/compilation.sh#L296-L307
Look:
In case you need the last version, grab a kernel source from daily builds: https://beta.armbian.com/pool/main/l/ (which I see now it's missing, bug)
