fix(errata): workaround for Neoverse-V1 erratum 2294912

Neoverse-V1 erratum 2294912 is a cat B erratum that applies to revisions
r0p0 - r1p1 and is still open. The workaround is to set bit[0] of
CPUACTLR2_EL1 to force PLDW/PFRM ST to behave like PLD/PRFM LD and not
cause invalidations to other PE caches.

SDEN can be found here:
https://developer.arm.com/documentation/SDEN1401781/latest



Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
Change-Id: Ia7afb4c42fe66b36fdf38a7d4281a0d168f68354