errata: workaround for Neoverse V1 errata 1774420

Neoverse V1 erratum 1774420 is a Cat B erratum present in r0p0 and
r1p0 of the V1 processor core. It is fixed in r1p1.

SDEN can be found here:
https://documentation-service.arm.com/static/60d499080320e92fa40b4625

Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>
Change-Id: I66e27b2518f73faeedd8615a1443a74b6a30f123
4 files changed