gpu: nova-core: add Falcon HAL method load_method()

gpu: nova-core: add Falcon HAL method load_method()

Some GPUs do not support using DMA to transfer code/data from system
memory to Falcon memory, and instead must use programmed I/O (PIO).
Add a function to the Falcon HAL to indicate whether a given GPU's
Falcons support DMA for this purpose.

Signed-off-by: Timur Tabi <ttabi@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://patch.msgid.link/20260122222848.2555890-10-ttabi@nvidia.com
[acourbot@nvidia.com: add short code to call into the HAL.]
[acourbot@nvidia.com: make `dma_load` private as per feedback.]
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>