fix(cpus): workaround for Cortex-A715 erratum 2331818

Cortex-A715 erratum 2331818 is a cat B erratum that applies to
revisions r0p0 and r1p0 and is fixed in r1p1. The workaround is to
set bit[20] of CPUACTLR2_EL1. Setting this bit is expected to have
a negligible performance impact.

SDEN can be found here:
https://developer.arm.com/documentation/SDEN2148827/latest

Change-Id: If3b1ed78b145ab6515cdd41135314350ed556381
Signed-off-by: Bipin Ravi <biprav01@u203721.austin.arm.com>
3 files changed