fix(cpus): modify the fix for Cortex-A75 erratum 764081

Apply the mitigation only for the revision and variant
mentioned in the SDEN.

SDEN Documentation:
https://developer.arm.com/documentation/SDEN859515/latest

Change-Id: Ifda1f4cb32bdec9a9af29397ddc03bf22a7a87fc
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
Signed-off-by: Sona Mathew <sonarebecca.mathew@arm.com>
(cherry picked from commit 7f152ea6856c7780424ec3e92b181d805a314f43)
diff --git a/include/lib/cpus/errata.h b/include/lib/cpus/errata.h
index a8eb84c..d8960d6 100644
--- a/include/lib/cpus/errata.h
+++ b/include/lib/cpus/errata.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2023, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2024, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -36,6 +36,15 @@
 void print_errata_status(void);
 void errata_print_msg(unsigned int status, const char *cpu, const char *id);
 
+#if ERRATA_A75_764081
+bool errata_a75_764081_applies(void);
+#else
+static inline bool errata_a75_764081_applies(void)
+{
+	return false;
+}
+#endif
+
 #if ERRATA_A520_2938996 || ERRATA_X4_2726228
 unsigned int check_if_affected_core(void);
 #endif