configure: Add ARM check.
diff --git a/configure.ac b/configure.ac
index 2b92883..c22fcc8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2334,6 +2334,7 @@
   *x86_64*)         WINE_CHECK_DEFINE([__x86_64__]) ;;
   *sparc*)          WINE_CHECK_DEFINE([__sparc__]) ;;
   *powerpc*)        WINE_CHECK_DEFINE([__powerpc__]) ;;
+  *arm*)            WINE_CHECK_DEFINE([__arm__]) ;;
 esac
 
 case $host_vendor in