add missing src symlink

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@5623 3c298f89-4303-0410-b956-a3cf2f4a3e73

diff --git a/target/linux/brcm-2.6/src b/target/linux/brcm-2.6/src
new file mode 120000 (symlink)
index 0000000..c8db533
--- /dev/null
+++ b/target/linux/brcm-2.6/src
@@ -0,0 +1 @@
+../brcm-2.4/src
\ No newline at end of file