bringing back tools/perf into the kernel.spec file

Hi, Continuing on the theme of bringing things into Fedora, one other task I'm currently looking at is bringing the tools building back into the kernel.spec file for testing purposes only. Fedora split the kernel-tools and userspace packages out into a separate repository at least two years ago. From my perspective, this has been a success since we've been able to avoid issues with tools breaking kernel builds and let the userspace tools build in a more standard way since we don't need to do all the weird hacks to build the kernel. This change has encountered some resistance downstream since their workflow involves more process and splitting out into a separate repository could potentially have more impact. I'm still working to resolve this but as an intermediate step I'd like to bring back the build commands into the kernel.spec file. We'd still keep building the tools in a separate repository but this would at least let us work towards the goal of having a common tree. If we decide to go with the split downstream, we will remove it again. If we decide to not go with the split downstream, I expect Fedora will want to follow and we'll need to bring the code back in anyway. I don't know exactly when I'll be getting to this but this is just a heads up that this work will be coming. Thanks, Laura