radv: Add temporary BO for transfer queues.

Some copy operations are poorly supported by the SDMA hardware,
meaning that the built-in packets don't support them, so we will
need to work around that by copying to and from a temporary BO.

The size of the temporary buffer was chosen so that it can fit
at least one full pixel row of the largest possible image.

Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Tatsuyuki Ishi <ishitatsuyuki@gmail.com>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25831>
4 files changed