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/renesas/rcar/pwrc/pwrc.c b/drivers/renesas/rcar/pwrc/pwrc.c
index f4c9d3a..32e04a7 100644
--- a/drivers/renesas/rcar/pwrc/pwrc.c
+++ b/drivers/renesas/rcar/pwrc/pwrc.c
@@ -148,7 +148,7 @@
 #define IS_CA57(c) 	((c) == RCAR_CLUSTER_CA57)
 #define IS_CA53(c) 	((c) == RCAR_CLUSTER_CA53)
 
-#ifndef __ASSEMBLY__
+#ifndef __ASSEMBLER__
 IMPORT_SYM(unsigned long, __system_ram_start__, SYSTEM_RAM_START);
 IMPORT_SYM(unsigned long, __system_ram_end__, SYSTEM_RAM_END);
 IMPORT_SYM(unsigned long, __SRAM_COPY_START__, SRAM_COPY_START);