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/bl32/tsp/tsp_private.h b/bl32/tsp/tsp_private.h
index e39f291..cbd527f 100644
--- a/bl32/tsp/tsp_private.h
+++ b/bl32/tsp/tsp_private.h
@@ -20,7 +20,7 @@
 #define TSP_ARGS_END		0x40
 
 
-#ifndef __ASSEMBLY__
+#ifndef __ASSEMBLER__
 
 #include <stdint.h>
 
@@ -148,6 +148,6 @@
 				uint64_t arg7);
 
 uint64_t tsp_main(void);
-#endif /* __ASSEMBLY__ */
+#endif /* __ASSEMBLER__ */
 
 #endif /* TSP_PRIVATE_H */