refactor(sgi): move apis and types to "nrd" prefix

Currently, functions and types internal to neoverse_rd platforms are
named with "sgi" as the prefix. Since common code and platforms are no
longer under the "sgi" umbrella, move the prefix to "nrd". This change
would amend the prefixes for functions, types and objects.

Signed-off-by: Rohit Mathew <Rohit.Mathew@arm.com>
Change-Id: I1080259b661081c535ab46f61df9e4563420bdb0
diff --git a/plat/arm/neoverse_rd/common/nrd_mem_prot.c b/plat/arm/neoverse_rd/common/nrd_mem_prot.c
index 09504e0..3a0b2fe 100644
--- a/plat/arm/neoverse_rd/common/nrd_mem_prot.c
+++ b/plat/arm/neoverse_rd/common/nrd_mem_prot.c
@@ -9,12 +9,12 @@
 #define SGI_DRAM1_NS_START	(TFTF_BASE + 0x4000000)
 #define SGI_DRAM1_NS_SIZE	0x10000000
 
-static const mem_region_t sgi_ram_ranges[] = {
+static const mem_region_t nrd_ram_ranges[] = {
 	{ SGI_DRAM1_NS_START, SGI_DRAM1_NS_SIZE },
 };
 
 const mem_region_t *plat_get_prot_regions(int *nelem)
 {
-	*nelem = ARRAY_SIZE(sgi_ram_ranges);
-	return sgi_ram_ranges;
+	*nelem = ARRAY_SIZE(nrd_ram_ranges);
+	return nrd_ram_ranges;
 }