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/plat/nvidia/tegra/include/tegra_platform.h b/plat/nvidia/tegra/include/tegra_platform.h
index b9c3782..d83ce48 100644
--- a/plat/nvidia/tegra/include/tegra_platform.h
+++ b/plat/nvidia/tegra/include/tegra_platform.h
@@ -30,7 +30,7 @@
 #define TEGRA_CHIPID_TEGRA21		U(0x21)
 #define TEGRA_CHIPID_TEGRA18		U(0x18)
 
-#ifndef __ASSEMBLY__
+#ifndef __ASSEMBLER__
 
 /*
  * Tegra chip ID major/minor identifiers
@@ -57,6 +57,6 @@
 bool tegra_platform_is_unit_fpga(void);
 bool tegra_platform_is_virt_dev_kit(void);
 
-#endif /* __ASSEMBLY__ */
+#endif /* __ASSEMBLER__ */
 
 #endif /* TEGRA_PLATFORM_H */