feat(handoff): port BL31-BL33 interface to fw handoff framework

The firmware handoff framework is a light weight mechanism for sharing
information between bootloader stages. Add support for this framework at
the handoff boundary between runtime firmware BL31 and NS software on FVP.

Change-Id: Ib02e0e4c20a39e32e06da667caf2ce5a28de1e28
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>
diff --git a/plat/arm/board/fvp/fvp_common.c b/plat/arm/board/fvp/fvp_common.c
index 283918b..c40a3ce 100644
--- a/plat/arm/board/fvp/fvp_common.c
+++ b/plat/arm/board/fvp/fvp_common.c
@@ -71,6 +71,14 @@
 					DEVICE2_SIZE,			\
 					MT_DEVICE | MT_RW | MT_SECURE)
 
+#if TRANSFER_LIST
+#ifdef FW_NS_HANDOFF_BASE
+#define MAP_FW_NS_HANDOFF MAP_REGION_FLAT(FW_NS_HANDOFF_BASE, \
+					  FW_HANDOFF_SIZE,    \
+					  MT_MEMORY | MT_RW | MT_NS)
+#endif
+#endif
+
 /*
  * Table of memory regions for various BL stages to map using the MMU.
  * This doesn't include Trusted SRAM as setup_page_tables() already takes care
@@ -183,6 +191,9 @@
 	ARM_MAP_GPT_L1_DRAM,
 	ARM_MAP_EL3_RMM_SHARED_MEM,
 #endif
+#ifdef MAP_FW_NS_HANDOFF
+	MAP_FW_NS_HANDOFF,
+#endif
 	{0}
 };