buildroot: Update to 2017.11.2 point release

There were no version changes to packages that are included in op-build.

Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/buildroot b/buildroot
index 65679be..4b6188e 160000
--- a/buildroot
+++ b/buildroot
@@ -1 +1 @@
-Subproject commit 65679be193a6981e3ac65bdda2fc3efbd62d85ef
+Subproject commit 4b6188e0f2397a013b91105828437c90a3b1dfb7