Squashed 'external/devlib/' changes from 1196e336..ff2268b7

ff2268b7 module/cpuidle: Add listing & setting governors
5042f474 module/cgroups: Skip disabled cgroup controllers
a5854269 android: Don't error if ADB is already running as root

git-subtree-dir: external/devlib
git-subtree-split: ff2268b715477a275d38f65d668fab96e4979421