gpu: nova-core: apply the one "use" item per line policy

gpu: nova-core: apply the one "use" item per line policy

As per [1], we need one "use" item per line, in order to reduce merge
conflicts. Furthermore, we need a trailing ", //" in order to tell
rustfmt(1) to leave it alone.

This does that for the entire nova-core driver.

[1] https://docs.kernel.org/rust/coding-guidelines.html#imports

Acked-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
[acourbot@nvidia.com: remove imports already in prelude as pointed out
by Danilo.]
[acourbot@nvidia.com: remove a few unneeded trailing `//`.]
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Message-ID: <20251107021006.434109-1-jhubbard@nvidia.com>