gpu: nova-core: bitfield: remove BitOr implementation

gpu: nova-core: bitfield: remove BitOr implementation

Using this operand can produce invalid values. It also doesn't bring
any benefit as one can use the builder pattern to assemble a new value.

Reported-by: Edwin Peer <epeer@nvidia.com>
Link: https://lore.kernel.org/rust-for-linux/F3853912-2C1C-4F9B-89B0-3168689F35B3@nvidia.com/
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Message-ID: <20251022-nova-bitfield-v1-3-73bc0988667b@nvidia.com>