(I am not part of any process with respect to this, embargoed or otherwise.)
Edit: the upstream commit is 58122bf1d856a4ea9581d62a07c557d997d46a19, called “x86/fpu: Default eagerfpu=on on all CPUs”, and it landed in early 2016. Greg K-H just submitted backports to all older supported kernels.
The point is: although relatively unlikely, it is still _possible_ that you need some mitigation even if you have newer hardware (Sandybridge or newer is where XSAVEOPT first showed up, I believe).
Disclaimer: I work on Linux at Intel.