Fix token and type declarations in getdate.y

Bison 3.5 adds a POSIX yacc compliance warning that %type should only
be applied to non-terminals.  Use %token for terminals in getdate.y.
Reported by Norm Green.

https://github.com/krb5/krb5/commit/d3356bc42191c1896ab06835a2fb245e00471420
Author: Greg Hudson <ghudson@mit.edu>
Commit: d3356bc42191c1896ab06835a2fb245e00471420
Branch: master
 src/kadmin/cli/getdate.y |   10 ++++------
 1 files changed, 4 insertions(+), 6 deletions(-)