[Cryptography] Improvements to RNG seeding in Linux 4.10

[Marshall Pierce]

It seems that Linux 4.10 will get its entropy pool populated early in boot via UEFI. 

Commits: 
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=568bc4e87033d232c5fd00d5b0cd22a2ccc04944 
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=636259880a7e7d3446a707dddebc799da94bdd0b

Credit to Kees Cook for the nice summary at https://outflux.net/blog/archives/2017/02/27/security-things-in-linux-v4-10/.