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/xlat_tables/xlat_mmu_helpers.h b/include/lib/xlat_tables/xlat_mmu_helpers.h
index 85effca..efe0dd5 100644
--- a/include/lib/xlat_tables/xlat_mmu_helpers.h
+++ b/include/lib/xlat_tables/xlat_mmu_helpers.h
@@ -50,7 +50,7 @@
 #define MMU_CFG_TTBR0		2
 #define MMU_CFG_PARAM_MAX	3
 
-#ifndef __ASSEMBLY__
+#ifndef __ASSEMBLER__
 
 #include <stdbool.h>
 #include <stdint.h>
@@ -86,6 +86,6 @@
 bool xlat_arch_is_granule_size_supported(size_t size);
 size_t xlat_arch_get_max_supported_granule_size(void);
 
-#endif /* __ASSEMBLY__ */
+#endif /* __ASSEMBLER__ */
 
 #endif /* XLAT_MMU_HELPERS_H */