fix(cpus): workaround for Cortex-A78C erratum 2779484

Cortex-A78C erratum 2779484 is a Cat B erratum that applies to
revisions r0p1 and r0p2 and is still open.

The workaround is to set the CPUACTLR3_EL1[47] bit to 1. Setting this
bit might have a small impact on power and negligible impact on
performance.

SDEN documentation:
https://developer.arm.com/documentation/SDEN2004089/latest

Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
Change-Id: I9a8c16a845c3ba6eb2f17a5119aa6ca09a0d27ed
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 112d8cb..0f10061 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -407,6 +407,10 @@
 # applies to revisions r0p0, r0p1 and r0p2 of the A78C cpu. It is still open.
 ERRATA_A78C_2772121 	?=0
 
+# Flag to apply erratum 2779484 workaround during reset. This erratum
+# applies to revisions r0p1 and r0p2 of the A78C cpu. It is still open.
+ERRATA_A78C_2779484 	?=0
+
 # Flag to apply erratum 1821534 workaround during reset. This erratum applies
 # to revisions r0p0 - r1p0 of the X1 cpu and fixed in r1p1.
 ERRATA_X1_1821534	?=0
@@ -1097,6 +1101,10 @@
 $(eval $(call assert_boolean,ERRATA_A78C_2772121))
 $(eval $(call add_define,ERRATA_A78C_2772121))
 
+# Process ERRATA_A78C_2779484 flag
+$(eval $(call assert_boolean,ERRATA_A78C_2779484))
+$(eval $(call add_define,ERRATA_A78C_2779484))
+
 # Process ERRATA_X1_1821534 flag
 $(eval $(call assert_boolean,ERRATA_X1_1821534))
 $(eval $(call add_define,ERRATA_X1_1821534))