Stable kernel updates

Stable kernels 5.4.4, 5.3.17, 4.19.90, and 4.14.159 have been released. They all containimportant fixes and users should upgrade.

Update: Stable kernels 5.4.5 and 5.3.18 have also been released. This is thelast 5.3.y kernel release and users should move to 5.4.y.