Add defines for aarch64

---

--- fdk-aac-0.1.2.orig/libFDK/include/FDK_archdef.h
+++ fdk-aac-0.1.2/libFDK/include/FDK_archdef.h
@@ -201,6 +201,13 @@ amm-info@iis.fraunhofer.de
 #define POW2COEFF_16BIT
 #define LDCOEFF_16BIT
 
+#elif defined(__aarch64__)  /* cppp replaced: elif */
+#define ARCH_PREFER_MULT_32x16
+#define SINETABLE_16BIT
+#define WINDOWTABLE_16BIT
+#define POW2COEFF_16BIT
+#define LDCOEFF_16BIT
+
 #else
 
   #error  >>>> Please set architecture characterization defines for your platform (FDK_HIGH_PERFORMANCE)! <<<<