It's been merged into the main kernel (i.e. the one maintained by Linus). Distributions can apply their own patches against the main kernel, which Debian did fo

It's been merged into the main kernel (i.e. the one maintained by Linus). Distributions can apply their own patches against the main kernel, which Debian did for RISC-V support. They don't have to apply the patches anymore. Functionality wise, what's been merged is only a subset.