Qnx: Add a build step for checking the device's debug token

This patch replaces the development mode check build step
by a debug token check which privdes more explicit error message
if the device's debug token is not valid.

Task-number: QTCREATORBUG-9673
Task-number: QTCREATORBUG-9001

Change-Id: I0a6148cc533156f3bfd6acbeb4abec2713b37b3c
Reviewed-by: Tobias Nätterlund <tobias.naetterlund@kdab.com>
Reviewed-by: Nicolas Arnaud-Cormos <nicolas@kdab.com>