Add more files to the distribution.

If it's checked into asn1 or a subdirectory thereof, put it into the
distribution.  (If it's not useful, why is it in Git?)

Change-Id: I4dac8a0d19a770db1513729cf71069a37f1d83fc
Reviewed-on: https://code.wireshark.org/review/3276
Reviewed-by: Guy Harris <guy@alum.mit.edu>