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/cpus/aarch32/cortex_a9.h b/include/lib/cpus/aarch32/cortex_a9.h
index 1fb0a92..a8c978a 100644
--- a/include/lib/cpus/aarch32/cortex_a9.h
+++ b/include/lib/cpus/aarch32/cortex_a9.h
@@ -25,7 +25,7 @@
  ******************************************************************************/
 #define PCR		p15, 0, c15, c0, 0
 
-#ifndef __ASSEMBLY__
+#ifndef __ASSEMBLER__
 #include <arch_helpers.h>
 DEFINE_COPROCR_RW_FUNCS(pcr, PCR)
 #endif