fix(cpus): workaround for Cortex-X3 erratum 3701769

Cortex-X3 erratum 3701769 that applies to r0p0, r1p0, r1p1 and r1p2
is still Open.

The workaround is for EL3 software that performs context save/restore
on a change of Security state to use a value of SCR_EL3.NS when
accessing ICH_VMCR_EL2 that reflects the Security state that owns the
data being saved or restored.

SDEN documentation:
https://developer.arm.com/documentation/SDEN-2055130/latest/

Change-Id: Ifd722e1bb8616ada2ad158297a7ca80b19a3370b
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index a879bb0..fb153f7 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -832,6 +832,11 @@
 # to revisions r0p0, r1p0 and r1p1 of the Cortex-X3 cpu, it is fixed in r1p2.
 CPU_FLAG_LIST += ERRATA_X3_2743088
 
+# Flag to apply erratum 3701769 workaround during context save/restore of
+# ICH_VMCR_EL2 reg. This erratum applies to revisions r0p0, r1p0, r1p1 and r1p2
+# of the Cortex-X3 cpu and is still open.
+CPU_FLAG_LIST += ERRATA_X3_3701769
+
 # Flag to apply erratum 2779509 workaround on reset. This erratum applies
 # to revisions r0p0, r1p0, r1p1 of the Cortex-X3 cpu, it is fixed in r1p2.
 CPU_FLAG_LIST += ERRATA_X3_2779509