plat/arm: rdn1edge: Correct mismatched parenthesis in makefile

This fixes build errors for rdn1edge

Change-Id: I63f7ebff68679e1e859f8786d4def4960c0f2ddf
Signed-off-by: Anders Dellien <anders.dellien@arm.com>
diff --git a/plat/arm/board/rdn1edge/platform.mk b/plat/arm/board/rdn1edge/platform.mk
index 819e892..b313426 100644
--- a/plat/arm/board/rdn1edge/platform.mk
+++ b/plat/arm/board/rdn1edge/platform.mk
@@ -47,7 +47,7 @@
 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),${FW_CONFIG})
+$(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}))