fix(cpus): workaround for Cortex-A720 erratum 2844092

Cortex-A720 erratum 2844092 is a Cat B erratum that is present
in revisions r0p0, r0p1 and is fixed in r0p2.

The workaround is to set bit[11] of CPUACTLR4_EL1 register.

SDEN documentation:
https://developer.arm.com/documentation/SDEN-2439421/latest

Change-Id: I3d8eacb26cba42774f1f31c3aae2a0e6fecec614
Signed-off-by: Sona Mathew <sonarebecca.mathew@arm.com>
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index c06bf9e..c9ff110 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -956,6 +956,10 @@
 # only to revision r0p0, r1p0 and r1p1. It is fixed in r1p2.
 CPU_FLAG_LIST += ERRATA_A715_2728106
 
+# Flag to apply erratum 2844092 workaround during reset. This erratum applies
+# to revisions r0p0 and r0p1. It is fixed in r0p2.
+CPU_FLAG_LIST += ERRATA_A720_2844092
+
 # Flag to apply erratum 2926083 workaround during reset. This erratum applies
 # to revisions r0p0 and r0p1. It is fixed in r0p2.
 CPU_FLAG_LIST += ERRATA_A720_2926083