feat(handoff): make tl generation flexible

Make the process of compiling a TL from DT source flexible. Provide a
top level recipe to make it easier for developers to build a transfer
list. Clean up integration of TLC into the build system.

Change-Id: I4466e27a457dfd5bf709dc3a360a2b63bf6030ce
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>
diff --git a/plat/arm/common/arm_bl31_setup.c b/plat/arm/common/arm_bl31_setup.c
index e91746b..65023bf 100644
--- a/plat/arm/common/arm_bl31_setup.c
+++ b/plat/arm/common/arm_bl31_setup.c
@@ -147,8 +147,7 @@
 	bl33_image_ep_info.spsr = arm_get_spsr_for_bl33_entry();
 	SET_SECURITY_STATE(bl33_image_ep_info.h.attr, NON_SECURE);
 
-	bl33_image_ep_info.args.arg0 =
-		FW_NS_HANDOFF_BASE + ARM_PRELOADED_DTB_OFFSET;
+	bl33_image_ep_info.args.arg0 = PLAT_ARM_TRANSFER_LIST_DTB_OFFSET;
 	bl33_image_ep_info.args.arg1 =
 		TRANSFER_LIST_HANDOFF_X1_VALUE(REGISTER_CONVENTION_VERSION);
 	bl33_image_ep_info.args.arg3 = FW_NS_HANDOFF_BASE;