fix(errata): workaround for Neoverse-V1 erratum 2372203

Neoverse-V1 erratum 2372203 is a cat B erratum that applies to revisions
r0p0 - r1p1 and is still open. The workaround is to set bit[40] of
CPUACTLR2_EL1 to disable folding of demand requests into older
prefetches with L2 miss requests outstanding.

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



Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
Change-Id: Ice8c2e5a0152972a35219c8245a2e07e646d0557