net: devmem: get netdev DMA device via new API

net: devmem: get netdev DMA device via new API

Switch to the new API for fetching DMA devices for a netdev. The API is
called with queue index 0 for now which is equivalent with the previous
behavior.

This patch will allow devmem to work with devices where the DMA device
is not stored in the parent device. mlx5 SFs are an example of such a
device.

Multi-PF netdevs are still problematic (as they were before this
change). Upcoming patches will address this for the rx binding.

Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20250827144017.1529208-5-dtatulea@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>