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/drivers/arm/css/sds/sds_private.h b/drivers/arm/css/sds/sds_private.h
index 2101dd0..d801a04 100644
--- a/drivers/arm/css/sds/sds_private.h
+++ b/drivers/arm/css/sds/sds_private.h
@@ -58,7 +58,7 @@
 #define SDS_REGION_REGIONSIZE_OFFSET		0x4
 #define SDS_REGION_DESC_SIZE			0x8
 
-#ifndef __ASSEMBLY__
+#ifndef __ASSEMBLER__
 #include <stddef.h>
 #include <stdint.h>
 
@@ -95,6 +95,6 @@
 	& SDS_REGION_SCH_VERSION_MASK)
 #define GET_SDS_REGION_SIZE(region)		((((region_desc_t *)(region))->reg[1]))
 
-#endif /* __ASSEMBLY__ */
+#endif /* __ASSEMBLER__ */
 
 #endif /* SDS_PRIVATE_H */