configure.target: Use cpu_include_dir="config/cpu/sparc" for all sparc targets.

	* configure.target: Use cpu_include_dir="config/cpu/sparc" for all
	sparc targets.
	* config/cpu/sparc/atomicity.h: New file.
	* config/cpu/sparc/sparc32/atomicity.h: Removed.
	* config/cpu/sparc/sparc64/atomicity.h: Removed.

From-SVN: r56896

libstdc++-v3/configure.target

@@ -97,11 +97,8 @@ case "${target_cpu}" in
   s390 | s390x)
     cpu_include_dir="cpu/s390"
     ;;
-  sparc64 | ultrasparc)
-    cpu_include_dir="cpu/sparc/sparc64"
-    ;;
-  sparc*)
-    cpu_include_dir="cpu/sparc/sparc32"
+  sparc* | ultrasparc)
+    cpu_include_dir="cpu/sparc"
     ;;
   x86_64*)
     cpu_include_dir="cpu/x86-64"