feat(rdn2): add board support for rdn2cfg2 variant

Add board support for variant 2 of RD-N2 platform which is a four chip
variant with 4 cores on each chip. The "CSS_SGI_PLATFORM_VARIANT" value
is 2 for multi-chip variant. The "CSS_SGI_CHIP_COUNT_MACRO" can be in
the range [1, 4] for multi-chip variant.

Signed-off-by: Aditya Angadi <aditya.angadi@arm.com>
Change-Id: I6412106e80e2f17704c796226c2ee9fe808705ba
diff --git a/plat/arm/css/sgi/include/sgi_soc_css_def_v2.h b/plat/arm/css/sgi/include/sgi_soc_css_def_v2.h
index bebc597..639b687 100644
--- a/plat/arm/css/sgi/include/sgi_soc_css_def_v2.h
+++ b/plat/arm/css/sgi/include/sgi_soc_css_def_v2.h
@@ -92,6 +92,12 @@
 						SOC_MEMCNTRL_SIZE,		\
 						MT_DEVICE | MT_RW | MT_SECURE)
 
+#define SOC_MEMCNTRL_MAP_DEVICE_REMOTE_CHIP(n)					\
+		MAP_REGION_FLAT(						\
+			CSS_SGI_REMOTE_CHIP_MEM_OFFSET(n) + SOC_MEMCNTRL_BASE,	\
+			SOC_MEMCNTRL_SIZE,					\
+			MT_DEVICE | MT_RW | MT_SECURE)
+
 /*
  * The bootsec_bridge controls access to a bunch of peripherals, e.g. the UARTs.
  */
diff --git a/plat/arm/css/sgi/sgi_plat_v2.c b/plat/arm/css/sgi/sgi_plat_v2.c
index 131cdf2..1a2a966 100644
--- a/plat/arm/css/sgi/sgi_plat_v2.c
+++ b/plat/arm/css/sgi/sgi_plat_v2.c
@@ -42,6 +42,15 @@
 	SOC_PLATFORM_PERIPH_MAP_DEVICE,
 	SOC_SYSTEM_PERIPH_MAP_DEVICE,
 	ARM_MAP_NS_DRAM1,
+#if CSS_SGI_CHIP_COUNT > 1
+	SOC_MEMCNTRL_MAP_DEVICE_REMOTE_CHIP(1),
+#endif
+#if CSS_SGI_CHIP_COUNT > 2
+	SOC_MEMCNTRL_MAP_DEVICE_REMOTE_CHIP(2),
+#endif
+#if CSS_SGI_CHIP_COUNT > 3
+	SOC_MEMCNTRL_MAP_DEVICE_REMOTE_CHIP(3),
+#endif
 #if ARM_BL31_IN_DRAM
 	ARM_MAP_BL31_SEC_DRAM,
 #endif