refactor(sgi): move from "sgi" to "neoverse_rd"

Currently, reference design platforms such as RD-N2, RD-N1-Edge,
RD-V1-MC, RD-V1 and SGI-575 utilize "css/sgi" as the common source
directory. The "sgi" prefix originated from the System Guidance for
Infrastructure (SGI) and was initially associated with the SGI-575
platform. However, subsequent platforms released were under the Neoverse
Reference Design product name.

To align with the Neoverse Reference Design nomenclature, rename the
common source directory from "css/sgi" to "css/neoverse_rd" and update
all file prefixes from "sgi" to "nrd."

Signed-off-by: Rohit Mathew <Rohit.Mathew@arm.com>
Change-Id: I3dcbb31b9ab202e82caf25218ba33c520dcea4e4
diff --git a/plat/arm/board/rdn2/include/rdn2_ras.h b/plat/arm/board/rdn2/include/rdn2_ras.h
index 1d9af60..7a97ea3 100644
--- a/plat/arm/board/rdn2/include/rdn2_ras.h
+++ b/plat/arm/board/rdn2/include/rdn2_ras.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2023-2024, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -7,7 +7,7 @@
 #ifndef RDN2_RAS_H
 #define RDN2_RAS_H
 
-#include <sgi_ras.h>
+#include <nrd_ras.h>
 
 extern struct plat_sgi_ras_config ras_config;