Add timeout support for SEV commands

Hi Greg,

Several peoples have reported the hung-task detector complains about an uninterruptible sleep in ccp driver with recent BIOS updates on Ryzen systems. During debug we found that recent BIOS updates have wrongly advertised that it supports SEV feature when it does not. We have made driver a bit more robust against this firmware bug. The patch is accepted in Linus tree for this. Due to some offset changes (and code restructure) I was not able to use upstream patch as-is. Doing a separate patch for 4.18, 4.17 and 4.16. Please let me know if you have any questions.

~ Brijesh