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/bl1/bl1.h b/include/bl1/bl1.h
index 937b8c7..d81f434 100644
--- a/include/bl1/bl1.h
+++ b/include/bl1/bl1.h
@@ -61,7 +61,7 @@
 #define is_fwu_fid(_fid) \
     ((_fid >= FWU_SMC_FID_START) && (_fid <= FWU_SMC_FID_END))
 
-#ifndef __ASSEMBLY__
+#ifndef __ASSEMBLER__
 
 #include <lib/cassert.h>
 
@@ -98,5 +98,5 @@
 void bl1_calc_bl2_mem_layout(const meminfo_t *bl1_mem_layout,
 			meminfo_t *bl2_mem_layout);
 
-#endif /* __ASSEMBLY__ */
+#endif /* __ASSEMBLER__ */
 #endif /* BL1_H */