configure: Add aarch64_be-linux-user target

Add target aarch64_be-linux-user. This allows a qemu-aarch64_be binary
to be built that will run big-endian aarch64 binaries.

Signed-off-by: Michael Weiser <michael.weiser@gmx.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-id: 20171220212308.12614-5-michael.weiser@gmx.de
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

configure

@@ -6439,7 +6439,7 @@ target_name=$(echo $target | cut -d '-' -f 1)
 target_bigendian="no"
 
 case "$target_name" in
-  armeb|hppa|lm32|m68k|microblaze|mips|mipsn32|mips64|moxie|or1k|ppc|ppcemb|ppc64|ppc64abi32|s390x|sh4eb|sparc|sparc64|sparc32plus|xtensaeb)
+  armeb|aarch64_be|hppa|lm32|m68k|microblaze|mips|mipsn32|mips64|moxie|or1k|ppc|ppcemb|ppc64|ppc64abi32|s390x|sh4eb|sparc|sparc64|sparc32plus|xtensaeb)
   target_bigendian=yes
   ;;
 esac
@@ -6494,7 +6494,8 @@ case "$target_name" in
     mttcg="yes"
     gdb_xml_files="arm-core.xml arm-vfp.xml arm-vfp3.xml arm-neon.xml"
   ;;
-  aarch64)
+  aarch64|aarch64_be)
+    TARGET_ARCH=aarch64
     TARGET_BASE_ARCH=arm
     bflt="yes"
     mttcg="yes"

default-configs/aarch64_be-linux-user.mak

@@ -0,0 +1 @@
+# Default configuration for aarch64_be-linux-user