assinar módulos dkms

criar chaves:
mkdir -p /var/lib/shim-signed/mok/
cd /var/lib/shim-signed/mok/
openssl req -new -x509 -newkey rsa:2048 -keyout MOK.priv -outform DER -out MOK.der -days 36500 -subj "/CN=dkms/"
openssl x509 -inform der -in MOK.der -out MOK.pem

Subscrever secure boot