kbuild: add svn revision information to setlocalversion

follow git and mercurial style, include uncommitted changes detect

Cc: Frans Pop <elendil@planet.nl>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

scripts/setlocalversion

@@ -45,3 +45,19 @@ if hgid=`hg id 2>/dev/null`; then
 	# All done with mercurial
 	exit
 fi
+
+# Check for svn and a svn repo.
+if rev=`svn info 2>/dev/null | grep '^Revision'`; then
+	rev=`echo $rev | awk '{print $NF}'`
+	changes=`svn status 2>/dev/null | grep '^[AMD]' | wc -l`
+
+	# Are there uncommitted changes?
+	if [ $changes != 0 ]; then
+		printf -- '-svn%s%s%s' "$rev" -dirty "$changes"
+	else
+		printf -- '-svn%s' "$rev"
+	fi
+
+	# All done with svn
+	exit
+fi