fix(cpus): workaround for Cortex-X4 erratum 2816013

Cortex-X4 erratum 2816013 is a Cat B erratum that applies
to all revisions <= r0p1 and is fixed in r0p2. This erratum
is only present when memory tagging is enabled.

The workaround is to set CPUACTLR5_EL1[14] to 1.

SDEN documentation:
https://developer.arm.com/documentation/SDEN-2432808/latest



Change-Id: I546044bde6e5eedd0abf61643d25e2dd2036df5c
Signed-off-by: Sona Mathew <sonarebecca.mathew@arm.com>