refactor(arm): allow platform specific SiP support

This patch introduces handler to add support for SiP calls to be
handled at EL3 for Arm platforms.

Consequently, the support for SPMD LSP is moved to corresponding
Arm platform SiP source file. This will allow us to add support
for a new SiP call in subsequent patch.

Change-Id: Ie29cb57fc622f96be3b67bebf34ce37cc82947d8
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
diff --git a/plat/nuvoton/npcm845x/platform.mk b/plat/nuvoton/npcm845x/platform.mk
index 5120cc6..cb5a553 100644
--- a/plat/nuvoton/npcm845x/platform.mk
+++ b/plat/nuvoton/npcm845x/platform.mk
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2015-2023, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2015-2023, Arm Limited and Contributors. All rights reserved.
 #
 # Copyright (c) 2017-2023 Nuvoton Ltd.
 #
@@ -273,9 +273,11 @@
 ifeq (${ARCH}, aarch64)
 BL31_SOURCES	+=	plat/arm/common/aarch64/execution_state_switch.c \
 		plat/arm/common/arm_sip_svc.c \
+		plat/arm/common/plat_arm_sip_svc.c \
 		lib/pmf/pmf_smc.c
 else
 BL32_SOURCES	+=	plat/arm/common/arm_sip_svc.c \
+		plat/arm/common/plat_arm_sip_svc.c \
 		lib/pmf/pmf_smc.c
 endif
 endif