fix(cpus): workaround for Cortex-X4 erratum 2897503

Cortex-X4 erratum 2897503 is a Cat B erratum that applies
to all revisions <= r0p1 and is fixed in r0p2.

The workaround is to set CPUACTLR4_EL1[8] to 1.

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

Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I3178a890b6f1307b310e817af75f8fdfb8668cc9
4 files changed