[SRU T/X] Fix KVM cpuid support for spec_ctrl

[Stefan Bader]

The Xenial backport is missing code to actually pass on info
from the edx register. In Trusty I messed up some details
(like correctly sorting the table and the non-intuitive 
ordering in an enum).

Adding those patches (and building a qemu package which also
handles the info) I was able to see spec_ctrl enabled inside
a KVM guest.

-Stefan