gpu: nova-core: avoid probing non-display/compute PCI functions

gpu: nova-core: avoid probing non-display/compute PCI functions

NovaCore has so far been too imprecise about figuring out if .probe()
has found a supported PCI PF (Physical Function). By that I mean:
.probe() sets up BAR0 (which involves a lot of very careful devres and
Device<Bound> details behind the scenes). And then if it is dealing with
a non-supported device such as the .1 audio PF on many GPUs, it fails
out due to an unexpected BAR0 size. We have been fortunate that the BAR0
sizes are different.

Really, we should be filtering on PCI class ID instead. These days I
think we can confidently pick out Nova's supported PF's via PCI class
ID. And if not, then we'll revisit.

The approach here is to filter on "Display VGA" or "Display 3D", which
is how PCI class IDs express "this is a modern GPU's PF".

Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Elle Rhumsaa <elle@weathered-steel.dev>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Link: https://lore.kernel.org/r/20250829223632.144030-5-jhubbard@nvidia.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>