fix(errata): workaround for Cortex A78C erratum 2242638

Cortex A78C erratum 2242638 is a Cat B erratum which applies to
revisions r0p1, r0p2 and is still open. The workaround is to apply
a CPU implementation specific specific patch sequence.

SDEN can be found here:
https://developer.arm.com/documentation/SDEN2004089/latest

Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
Change-Id: I35d385245a04a39b87be71c1a42312f75e1152e5
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 19e611c..2c08a27 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -365,6 +365,10 @@
 # to revisions r0p1 and r0p2 of the A78C cpu. It is still open.
 ERRATA_A78C_2132064	?=0
 
+# Flag to apply erratum 2242638 workaround during reset. This erratum applies
+# to revisions r0p1 and r0p2 of the A78C cpu. It is still open.
+ERRATA_A78C_2242638	?=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
@@ -923,6 +927,10 @@
 $(eval $(call assert_boolean,ERRATA_A78C_2132064))
 $(eval $(call add_define,ERRATA_A78C_2132064))
 
+# Process ERRATA_A78C_2242638 flag
+$(eval $(call assert_boolean,ERRATA_A78C_2242638))
+$(eval $(call add_define,ERRATA_A78C_2242638))
+
 # Process ERRATA_X1_1821534 flag
 $(eval $(call assert_boolean,ERRATA_X1_1821534))
 $(eval $(call add_define,ERRATA_X1_1821534))