Rename --*able-softmmu --*able-system.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1788 c046a42c-6fe2-441c-8c8c-71466251a162

configure

@@ -211,9 +211,9 @@ for opt do
   ;;
   --disable-gcc-check) check_gcc="no"
   ;;
-  --disable-softmmu) softmmu="no"
+  --disable-system) softmmu="no"
   ;;
-  --enable-softmmu) softmmu="yes"
+  --enable-system) softmmu="yes"
   ;;
   --disable-user) user="no"
   ;;