FVP: restrict dynamic config to Unix build environment

This patch restricts building the dynamic config DTBs to the Unix
build environment as the Device Tree compiler may not be available
on other build environments.

Change-Id: Ie690e80010a174300e966240fd977b37561156e0
Signed-off-by: Soby Mathew <soby.mathew@arm.com>

plat/arm/board/fvp/platform.mk

@@ -159,7 +159,8 @@ BL31_SOURCES		+=	drivers/arm/smmu/smmu_v3.c			\
 				${FVP_INTERCONNECT_SOURCES}			\
 				${FVP_SECURITY_SOURCES}
 
-# Add the FDT_SOURCES and options for Dynamic Config
+# Add the FDT_SOURCES and options for Dynamic Config (only for Unix env)
+ifdef UNIX_MK
 FVP_HW_CONFIG_DTS	:=	fdts/${FVP_DT_PREFIX}.dts
 FDT_SOURCES		+=	plat/arm/board/fvp/fdts/${PLAT}_tb_fw_config.dts
 FVP_TB_FW_CONFIG	:=	${BUILD_PLAT}/fdts/${PLAT}_tb_fw_config.dtb
@@ -172,6 +173,7 @@ $(eval FVP_HW_CONFIG	:=	${BUILD_PLAT}/$(patsubst %.dts,%.dtb,$(FVP_HW_CONFIG_DTS
 
 # Add the HW_CONFIG to FIP and specify the same to certtool
 $(eval $(call TOOL_ADD_PAYLOAD,${FVP_HW_CONFIG},--hw-config))
+endif
 
 # Disable the PSCI platform compatibility layer
 ENABLE_PLAT_COMPAT	:= 	0