libmodprobe: make available in vendor

A toolbox implementation of modprobe will require libmodprobe.

Change-Id: I7790576b828ad8cd5fae0c51926d8da9fb540d30
diff --git a/libmodprobe/Android.bp b/libmodprobe/Android.bp
index a2824d1..78da46c 100644
--- a/libmodprobe/Android.bp
+++ b/libmodprobe/Android.bp
@@ -3,6 +3,7 @@
     cflags: [
         "-Werror",
     ],
+    vendor_available: true,
     recovery_available: true,
     srcs: [
         "libmodprobe.cpp",