fix(errata): workaround for DSU-110 erratum 2313941

DSU-110 erratum 2313941 is a Cat B erratum and applies to revisions
r0p0, r1p0, r2p0, r2p1, r3p0, r3p1 and is still open.

The workaround sets IMP_CLUSTERACTLR_EL1[16:15] bits to 0b11 to disable
clock gating of the SCLK domain. This will increase the idle power
consumption.

This patch applies the fix for Cortex-X2/A510/A710 and Neoverse N2.

SDEN can be found here:
https://developer.arm.com/documentation/SDEN1781796/latest

Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
Change-Id: I54d948b23e8e01aaf1898ed9fe4e2255dd209318
Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
diff --git a/include/lib/cpus/aarch64/dsu_def.h b/include/lib/cpus/aarch64/dsu_def.h
index 0969acf..577de61 100644
--- a/include/lib/cpus/aarch64/dsu_def.h
+++ b/include/lib/cpus/aarch64/dsu_def.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2022, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -32,6 +32,7 @@
 #define CLUSTERACTLR_EL1	S3_0_C15_C3_3
 
 #define CLUSTERACTLR_EL1_DISABLE_CLOCK_GATING	(ULL(1) << 15)
+#define CLUSTERACTLR_EL1_DISABLE_SCLK_GATING	(ULL(3) << 15)
 
 /********************************************************************
  * Masks applied for DSU errata workarounds