pki: Remove duplicate and unused code
Remove duplicate code previously used only in server side to generate
signatures. Currently the code used to generate the signature is the
same for both client and server.
Signed-off-by: Anderson Toshiyuki Sasaki <email@example.com>
Reviewed-by: Jakub Jelen <firstname.lastname@example.org>
Reviewed-by: Andreas Schneider <email@example.com>