colibri_vf: disable undefined instruction events in user debug

colibri_vf: disable undefined instruction events in user debug

It turns out that OpenSSL calls undefined instructions to detect
ARM capabilities at runtime (via SIGILL handler). This leads to
stack traces e.g. when logging in using SSH:
  [  877.464442] sshd (613): undefined instruction: pc=76ee2da8
  ...

Disable undefined instruction events since it is used as an
autodetecion mechanism.

Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Acked-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Igor Opaniuk <igor.opaniuk@toradex.com>