nvidia_modprobe: allow reading driver parameters

On Debian Sid nvidia_modprobe is not permissive enough:

```
type=AVC msg=audit(1598788812.837:495): apparmor="DENIED"
operation="open" profile="nvidia_modprobe"
name="/proc/driver/nvidia/params" pid=31586 comm="nvidia-modprobe"
requested_mask="r" denied_mask="r" fsuid=0 ouid=0
```

Update profile to all reading /proc/driver/nvidia/params

Fixes Debian bug 969267 [0]

[0] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=969267

profiles/apparmor.d/nvidia_modprobe

@@ -29,6 +29,7 @@ profile nvidia_modprobe {
   @{sys}/bus/pci/devices/ r,
   @{sys}/devices/pci[0-9]*/**/config r,
   @{PROC}/devices r,
+  @{PROC}/driver/nvidia/params r,
   @{PROC}/modules r,
   @{PROC}/sys/kernel/modprobe r,