fs: add kernel modules for AFS client

 - add/separate crypto modules
 - add fscache support
 - add rxrpc module which is required for AFS
 - add afs module

Signed-Off-By: Nathaniel Wesley Filardo <8S9K8UGO5JGPI3U067229BBACKMQIGVH@cmx.ietfng.org>
Acked-by: Zoltan HERPAI <wigyori@uid0.hu>



git-svn-id: svn://svn.openwrt.org/openwrt/trunk@40587 3c298f89-4303-0410-b956-a3cf2f4a3e73