Replace __ASSEMBLY__ with compiler-builtin __ASSEMBLER__

NOTE: __ASSEMBLY__ macro is now deprecated in favor of __ASSEMBLER__.

All common C compilers predefine a macro called __ASSEMBLER__ when
preprocessing a .S file. There is no reason for TF-A to define it's own
__ASSEMBLY__ macro for this purpose instead. To unify code with the
export headers (which use __ASSEMBLER__ to avoid one extra dependency),
let's deprecate __ASSEMBLY__ and switch the code base over to the
predefined standard.

Change-Id: Id7d0ec8cf330195da80499c68562b65cb5ab7417
Signed-off-by: Julius Werner <jwerner@chromium.org>
diff --git a/plat/renesas/rcar/include/platform_def.h b/plat/renesas/rcar/include/platform_def.h
index bbe4a54..b7f0ca1 100644
--- a/plat/renesas/rcar/include/platform_def.h
+++ b/plat/renesas/rcar/include/platform_def.h
@@ -7,7 +7,7 @@
 #ifndef PLATFORM_DEF_H
 #define PLATFORM_DEF_H
 
-#ifndef __ASSEMBLY__
+#ifndef __ASSEMBLER__
 #include <stdlib.h>
 #endif