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/include/lib/smccc.h b/include/lib/smccc.h
index 94c39d2..76e6023 100644
--- a/include/lib/smccc.h
+++ b/include/lib/smccc.h
@@ -87,7 +87,7 @@
 #define SMC_FROM_SECURE		(U(0) << 0)
 #define SMC_FROM_NON_SECURE	(U(1) << 0)
 
-#ifndef __ASSEMBLY__
+#ifndef __ASSEMBLER__
 
 #include <stdint.h>
 
@@ -155,5 +155,5 @@
 		smc_uuid_word((_uuid).node[2], (_uuid).node[3],			\
 			      (_uuid).node[4], (_uuid).node[5]))
 
-#endif /*__ASSEMBLY__*/
+#endif /*__ASSEMBLER__*/
 #endif /* SMCCC_H */