loader: add nvidia modules to the loader blacklist

[kevans]

Summary

It is known that nvidia modules, like the drm modules that are already
present, will panic if loaded in early boot rather than later. Pop them
into our list to deny loading them if someone were to add, e.g.,
nvidia-modeset_load="YES", to their loader.conf. This doesn't prevent
them from being loaded if one drops to the loader prompt, but it does
prevent the standard user from easy foot-shooting if they find old or
inaccurate information out in the wild.

[kbowling]

'nvidia-drm' would also be belong in this list

[ashafer]

+1 to including nvidia-drm for consistency, although I think since it's dependent on the others it will fail to load as-is.

[kevans]

In D51644#1179614, @kbowling wrote:

'nvidia-drm' would also be belong in this list

Added locally, thanks!