allwinner: Add BL32 (corresponds to Trusted OS) support

This patch is an attempt to run Trusted OS (OP-TEE OS being one of them) along
side BL31 image.

ATF supports multiple SPD's that can take dispatcher name (opteed for OP-TEE OS)
as an input using the 'SPD=<dispatcher name>' option during bl31 build.

Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>
diff --git a/plat/allwinner/common/include/platform_def.h b/plat/allwinner/common/include/platform_def.h
index ca7db2f..2752aa4 100644
--- a/plat/allwinner/common/include/platform_def.h
+++ b/plat/allwinner/common/include/platform_def.h
@@ -42,4 +42,10 @@
 #define PLATFORM_MMAP_REGIONS		4
 #define PLATFORM_STACK_SIZE		(0x1000 / PLATFORM_CORE_COUNT)
 
+#ifndef SPD_none
+#ifndef BL32_BASE
+#define BL32_BASE			SUNXI_DRAM_BASE
+#endif
+#endif
+
 #endif /* __PLATFORM_DEF_H__ */