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/rdn1edge/rdn1edge_plat.c b/plat/arm/board/rdn1edge/rdn1edge_plat.c
index 9a87535..9130751 100644
--- a/plat/arm/board/rdn1edge/rdn1edge_plat.c
+++ b/plat/arm/board/rdn1edge/rdn1edge_plat.c
@@ -8,8 +8,9 @@
 #include <drivers/arm/gic600_multichip.h>
 #include <plat/arm/common/plat_arm.h>
 #include <plat/common/platform.h>
-#include <sgi_soc_platform_def.h>
-#include <sgi_plat.h>
+
+#include <nrd_plat.h>
+#include <nrd_soc_platform_def.h>
 
 #if defined(IMAGE_BL31)
 static const mmap_region_t rdn1edge_dynamic_mmap[] = {