target-tilegx: Add TILE-Gx building files

Add related configuration and make files for tilegx.
The target can now build, though not run anything.
Signed-off-by: NChen Gang <gang.chen.5i5j@gmail.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Message-Id: <BLU436-SMTP1588E5A03AD5E94B07E988B9660@phx.gbl>
Signed-off-by: NRichard Henderson <rth@twiddle.net>

configure

@@ -5450,6 +5450,8 @@ case "$target_name" in
   s390x)
     gdb_xml_files="s390x-core64.xml s390-acr.xml s390-fpr.xml s390-vx.xml s390-cr.xml"
   ;;
+  tilegx)
+  ;;
   tricore)
   ;;
   unicore32)

default-configs/tilegx-linux-user.mak

+# Default configuration for tilegx-linux-user

target-tilegx/Makefile.objs

+obj-y += cpu.o translate.o helper.o