fix(cpus): workaround for Cortex-A78C erratum 2683027

Cortex-A78C erratum 2683027 is a cat B erratum that applies to
revisions r0p1 - r0p2 and is still open. The workaround is to
execute a specific code sequence in EL3 during reset.

SDEN can be found here:
https://developer.arm.com/documentation/SDEN-2004089/latest



Change-Id: I2bf9e675f48b62b4cd203100f7df40f4846aafa8
Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>