Add support for Neoverse-N2 CPUs.

Enable basic support for Neoverse-N2 CPUs.

Signed-off-by: Javier Almansa Sobrino <javier.almansasobrino@arm.com>
Change-Id: I498adc2d9fc61ac6e1af8ece131039410872e8ad
diff --git a/lib/cpus/aarch64/neoverse_n_common.S b/lib/cpus/aarch64/neoverse_n_common.S
new file mode 100644
index 0000000..b816342
--- /dev/null
+++ b/lib/cpus/aarch64/neoverse_n_common.S
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <asm_macros.S>
+#include <neoverse_n_common.h>
+
+	.global is_scu_present_in_dsu
+
+/*
+ * Check if the SCU L3 Unit is present on the DSU
+ * 1-> SCU present
+ * 0-> SCU not present
+ *
+ * This function is implemented as weak on dsu_helpers.S and must be
+ * overwritten for Neoverse Nx cores.
+ */
+
+func is_scu_present_in_dsu
+	mrs	x0, CPUCFR_EL1
+	ubfx	x0, x0, #SCU_SHIFT, #1
+	eor	x0, x0, #1
+	ret
+endfunc is_scu_present_in_dsu