refactor(sgi): move neoverse_rd out of css

Currently, neoverse_rd is hosted under the "css" directory. However,
"css" directory is more relevant for hosting css definitions and
corresponding sources. Since neoverse_rd hosts source and header for css
and soc, move neoverse_rd from css to board folder. Consolidate common
sources and headers under neoverse_rd/common. Additionally, group RD-V1,
RD-V1-MC, RD-N2, RD-N1-Edgex2 and SGI-575 within neoverse_rd/platform.
With the changes in this commit, the tree view would look as follows:

plat/arm/board/neoverse_rd/
├── common
│   ├── arch
│   ├── include
│   └── ras
└── platform
    ├── rdn1edge
    ├── rdn2
    ├── rdv1
    ├── rdv1mc
    └── sgi575

Signed-off-by: Rohit Mathew <Rohit.Mathew@arm.com>
Change-Id: Iaccc86bc9d415f5c045c834902241fcf3c00277b
diff --git a/plat/arm/board/neoverse_rd/platform/rdn2/platform.mk b/plat/arm/board/neoverse_rd/platform/rdn2/platform.mk
new file mode 100644
index 0000000..fb9ff35
--- /dev/null
+++ b/plat/arm/board/neoverse_rd/platform/rdn2/platform.mk
@@ -0,0 +1,131 @@
+# Copyright (c) 2020-2024, Arm Limited and Contributors. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+RD_N2_VARIANTS	:= 0 1 2 3
+ifneq ($(CSS_SGI_PLATFORM_VARIANT),\
+	$(filter $(CSS_SGI_PLATFORM_VARIANT),$(RD_N2_VARIANTS)))
+ $(error "CSS_SGI_PLATFORM_VARIANT for RD-N2 should be 0, 1, 2 or 3, currently \
+	set to ${CSS_SGI_PLATFORM_VARIANT}.")
+endif
+
+$(eval $(call CREATE_SEQ,SEQ,4))
+ifneq ($(CSS_SGI_CHIP_COUNT),$(filter $(CSS_SGI_CHIP_COUNT),$(SEQ)))
+ $(error  "Chip count for RD-N2-MC should be either $(SEQ) \
+ currently it is set to ${CSS_SGI_CHIP_COUNT}.")
+endif
+
+# RD-N2 platform uses GIC-700 which is based on GICv4.1
+GIC_ENABLE_V4_EXTN	:=	1
+GIC_EXT_INTID		:=	1
+
+#Enable GIC Multichip Extension only for Multichip Platforms
+ifeq (${CSS_SGI_PLATFORM_VARIANT}, 2)
+GICV3_IMPL_GIC600_MULTICHIP	:=	1
+endif
+
+override CSS_SYSTEM_GRACEFUL_RESET	:= 1
+override EL3_EXCEPTION_HANDLING		:= 1
+
+include plat/arm/board/neoverse_rd/common/nrd-common.mk
+
+RDN2_BASE		=	plat/arm/board/neoverse_rd/platform/rdn2
+
+PLAT_INCLUDES		+=	-I${RDN2_BASE}/include/
+
+SGI_CPU_SOURCES		:=	lib/cpus/aarch64/neoverse_n2.S \
+				lib/cpus/aarch64/neoverse_v2.S
+
+PLAT_BL_COMMON_SOURCES	+=	${NRD_COMMON_BASE}/nrd_plat_v2.c
+
+BL1_SOURCES		+=	${SGI_CPU_SOURCES}			\
+				${RDN2_BASE}/rdn2_err.c
+
+BL2_SOURCES		+=	${RDN2_BASE}/rdn2_plat.c		\
+				${RDN2_BASE}/rdn2_security.c		\
+				${RDN2_BASE}/rdn2_err.c			\
+				lib/utils/mem_region.c			\
+				drivers/arm/tzc/tzc400.c		\
+				plat/arm/common/arm_tzc400.c		\
+				plat/arm/common/arm_nor_psci_mem_protect.c
+
+BL31_SOURCES		+=	${SGI_CPU_SOURCES}			\
+				${RDN2_BASE}/rdn2_plat.c		\
+				${RDN2_BASE}/rdn2_topology.c		\
+				drivers/cfi/v2m/v2m_flash.c		\
+				lib/utils/mem_region.c			\
+				plat/arm/common/arm_nor_psci_mem_protect.c
+
+ifeq (${TRUSTED_BOARD_BOOT}, 1)
+BL1_SOURCES		+=	${RDN2_BASE}/rdn2_trusted_boot.c
+BL2_SOURCES		+=	${RDN2_BASE}/rdn2_trusted_boot.c
+endif
+
+ifeq (${CSS_SGI_PLATFORM_VARIANT}, 2)
+BL31_SOURCES	+=	drivers/arm/gic/v3/gic600_multichip.c
+
+# Enable dynamic addition of MMAP regions in BL31
+BL31_CFLAGS		+=	-DPLAT_XLAT_TABLES_DYNAMIC
+endif
+
+ifeq (${ENABLE_FEAT_RAS}-${HANDLE_EA_EL3_FIRST_NS},1-1)
+BL31_SOURCES		+=	${RDN2_BASE}/rdn2_ras.c			\
+				${NRD_COMMON_BASE}/ras/nrd_ras_common.c	\
+				${NRD_COMMON_BASE}/ras/nrd_ras_sram.c	\
+				${NRD_COMMON_BASE}/ras/nrd_ras_cpu.c
+endif
+
+# Add the FDT_SOURCES and options for Dynamic Config
+FDT_SOURCES		+=	${RDN2_BASE}/fdts/${PLAT}_fw_config.dts	\
+				${RDN2_BASE}/fdts/${PLAT}_tb_fw_config.dts
+FW_CONFIG		:=	${BUILD_PLAT}/fdts/${PLAT}_fw_config.dtb
+TB_FW_CONFIG		:=	${BUILD_PLAT}/fdts/${PLAT}_tb_fw_config.dtb
+
+# Add the FW_CONFIG to FIP and specify the same to certtool
+$(eval $(call TOOL_ADD_PAYLOAD,${FW_CONFIG},--fw-config,${FW_CONFIG}))
+# Add the TB_FW_CONFIG to FIP and specify the same to certtool
+$(eval $(call TOOL_ADD_PAYLOAD,${TB_FW_CONFIG},--tb-fw-config,${TB_FW_CONFIG}))
+
+FDT_SOURCES		+=	${RDN2_BASE}/fdts/${PLAT}_nt_fw_config.dts
+NT_FW_CONFIG		:=	${BUILD_PLAT}/fdts/${PLAT}_nt_fw_config.dtb
+
+# Add the NT_FW_CONFIG to FIP and specify the same to certtool
+$(eval $(call TOOL_ADD_PAYLOAD,${NT_FW_CONFIG},--nt-fw-config))
+
+ifeq (${SPMC_AT_EL3}, 1)
+STMM_CONFIG_DTS		:=	${RDN2_BASE}/fdts/${PLAT}_stmm_sel0_manifest.dts
+FDT_SOURCES		+=	${STMM_CONFIG_DTS}
+TOS_FW_CONFIG		:=	${BUILD_PLAT}/fdts/$(notdir $(basename ${STMM_CONFIG_DTS})).dtb
+
+# Add the TOS_FW_CONFIG to FIP and specify the same to certtool
+$(eval $(call TOOL_ADD_PAYLOAD,${TOS_FW_CONFIG},--tos-fw-config,${TOS_FW_CONFIG}))
+endif
+
+override CTX_INCLUDE_AARCH32_REGS	:= 0
+override ENABLE_FEAT_AMU		:= 1
+
+# Enable the flag since RD-N2 has a system level cache
+NEOVERSE_Nx_EXTERNAL_LLC		:=	1
+
+# Enable N2 CPU errata workarounds
+ERRATA_N2_2002655	:=	1
+ERRATA_N2_2009478	:=	1
+ERRATA_N2_2067956	:=	1
+ERRATA_N2_2025414	:=	1
+ERRATA_N2_2189731	:=	1
+ERRATA_N2_2138956	:=	1
+ERRATA_N2_2138953	:=	1
+ERRATA_N2_2242415	:=	1
+ERRATA_N2_2138958	:=	1
+ERRATA_N2_2242400	:=	1
+ERRATA_N2_2280757	:=	1
+ERRATA_N2_2326639	:=	1
+ERRATA_N2_2340933	:=	1
+ERRATA_N2_2346952	:=	1
+ERRATA_N2_2376738	:=	1
+ERRATA_N2_2388450	:=	1
+ERRATA_N2_2743014	:=	1
+ERRATA_N2_2743089	:=	1
+ERRATA_N2_2728475	:=	1
+ERRATA_N2_2779511	:=	1