nfsd: Do not accept audit/alarm ACEs for the NFSv4 server

The UFS and ZFS file systems only support Allow/Deny ACEs
in the NFSv4 ACLs. This patch does not allow the server
to parse Audit/Alarm ACEs. The NFSv4 client is still
allowed to pase Audit/Alarm ACEs, since non-FreeBSD NFSv4
servers may use them.

This patch should not have a significant effect, since the
UFS and ZFS file systems will not handle these ACEs anyhow.
It simply serves as an additional "safety belt" for the
NFSv4 server.

(cherry picked from commit a91a57846b5863b7ac4687cf202bb9496e028ab5)