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/services/std_svc/spm_mm/spm_private.h b/services/std_svc/spm_mm/spm_private.h
index 8e94a28..ba94a4d 100644
--- a/services/std_svc/spm_mm/spm_private.h
+++ b/services/std_svc/spm_mm/spm_private.h
@@ -29,7 +29,7 @@
 #define SP_C_RT_CTX_SIZE	0x60
 #define SP_C_RT_CTX_ENTRIES	(SP_C_RT_CTX_SIZE >> DWORD_SHIFT)
 
-#ifndef __ASSEMBLY__
+#ifndef __ASSEMBLER__
 
 #include <stdint.h>
 
@@ -66,6 +66,6 @@
 					  u_register_t pages_count,
 					  u_register_t smc_attributes);
 
-#endif /* __ASSEMBLY__ */
+#endif /* __ASSEMBLER__ */
 
 #endif /* SPM_PRIVATE_H */