[SRU][Trusty][PATCH 0/2] CVE-2017-5715 - SpectreRSB sub-variant of Spectre v2

[Tyler Hicks]

This fixes the SpectreRSB sub-variant of Spectre variant 2. This sub-variant
didn't receive a new CVE. This Trusty backport requires an additional pre-req
patch which was already applied in Xenial and Bionic.

Tyler