Add support for Cortex-A75 and Cortex-A55 CPUs

Both Cortex-A75 and Cortex-A55 CPUs use the ARM DynamIQ Shared Unit
(DSU). The power-down and power-up sequences are therefore mostly
managed in hardware, and required software operations are considerably
simpler.

Change-Id: I68b30e6e1ebe7c041d5e67f39c59f08575fc7ecc
Co-authored-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/include/lib/cpus/aarch64/cortex_a75.h b/include/lib/cpus/aarch64/cortex_a75.h
new file mode 100644
index 0000000..1ffe20b
--- /dev/null
+++ b/include/lib/cpus/aarch64/cortex_a75.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __CORTEX_A75_H__
+#define __CORTEX_A75_H__
+
+/* Cortex-A75 MIDR */
+#define CORTEX_A75_MIDR		0x410fd0a0
+
+/*******************************************************************************
+ * CPU Extended Control register specific definitions.
+ ******************************************************************************/
+#define CORTEX_A75_CPUPWRCTLR_EL1	S3_0_C15_C2_7
+#define CORTEX_A75_CPUECTLR_EL1		S3_0_C15_C1_4
+
+/* Definitions of register field mask in CORTEX_A75_CPUPWRCTLR_EL1 */
+#define CORTEX_A75_CORE_PWRDN_EN_MASK	0x1
+
+#endif /* __CORTEX_A75_H__ */