ceph: select FS_ENCRYPTION_ALGS if FS_ENCRYPTION

The kconfig options for filesystems that support FS_ENCRYPTION are
supposed to select FS_ENCRYPTION_ALGS.  This is needed to ensure that
required crypto algorithms get enabled as loadable modules or builtin as
is appropriate for the set of enabled filesystems.  Do this for CEPH_FS
so that there aren't any missing algorithms if someone happens to have
CEPH_FS as their only enabled filesystem that supports encryption.

Cc: stable@vger.kernel.org
Fixes: f061feda ("ceph: add fscrypt ioctls and ceph.fscrypt.auth vxattr")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>