CPU: Add Aarch64 support

The __aarch64__ defines Aarch64, while __AARCH64EB__ defines bigendian
and __AARCH64EL__ little endian.  Only little endian tested, no big
endian toolchain exists yet.

Change-Id: Ieded9bdb0557ad1e1f3a5b08fbe210df23079e5e
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

CPU.h.in

@@ -98,6 +98,14 @@
 #elif defined(__SYSC_ZARCH__)
 # define @KWSYS_NAMESPACE@_CPU_ENDIAN_ID @KWSYS_NAMESPACE@_CPU_ENDIAN_ID_BIG
 
+/* Aarch64 */
+#elif defined(__aarch64__)
+# if !defined(__AARCH64EB__)
+#  define @KWSYS_NAMESPACE@_CPU_ENDIAN_ID @KWSYS_NAMESPACE@_CPU_ENDIAN_ID_LITTLE
+# else
+#  define @KWSYS_NAMESPACE@_CPU_ENDIAN_ID @KWSYS_NAMESPACE@_CPU_ENDIAN_ID_BIG
+# endif
+
 /* Unknown CPU */
 #else
 # define @KWSYS_NAMESPACE@_CPU_ENDIAN_ID 0