ARM: Move __secure definition to common asm/secure.h

sunxi and i.mx7 both define the __secure modifier to put functions in
the secure section. Move this to a common place.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
diff --git a/arch/arm/include/asm/secure.h b/arch/arm/include/asm/secure.h
index effdb18..6d9088b 100644
--- a/arch/arm/include/asm/secure.h
+++ b/arch/arm/include/asm/secure.h
@@ -3,6 +3,8 @@
 
 #include <config.h>
 
+#define __secure __attribute__ ((section ("._secure.text")))
+
 #ifdef CONFIG_ARMV7_SECURE_BASE
 /*
  * Warning, horror ahead.