gpu: host1x: Set up device DMA parameters

gpu: host1x: Set up device DMA parameters

In order to store device DMA parameters, the DMA framework depends on
the device's dma_parms field to point at a valid memory location. Add
backing storage for this in struct host1x_memory_context and point to
it.

Reported-by: Jonathan Hunter <jonathanh@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240916133320.368620-1-thierry.reding@gmail.com