Revert "drm/nouveau: set DMA mask before creating the flush page"

Revert "drm/nouveau: set DMA mask before creating the flush page"

This reverts commit ebe755605082eddff80eafe0c50915b1366ee98f.

Tested the latest kernel on my GB203 and this seems to break it somehow.

Nov 09 04:16:14 bighp kernel: nouveau 0000:02:00.0: gsp: GSP-FMC boot failed (mbox: 0x0000000b)
Nov 09 04:16:14 bighp kernel: nouveau 0000:02:00.0: gsp: init failed, -5
Nov 09 04:16:14 bighp kernel: nouveau 0000:02:00.0: init failed with -5
Nov 09 04:16:14 bighp kernel: nouveau: drm:00000000:00000080: init failed with -5
Nov 09 04:16:14 bighp kernel: nouveau 0000:02:00.0: drm: Device allocation failed: -5
Nov 09 04:16:14 bighp kernel: nouveau 0000:02:00.0: probe with driver nouveau failed with error -5

Not sure why, I went over the patch and thought it should have worked, but there must be some
32-bit problem maybe in the FMC boot path.

Signed-off-by: Dave Airlie <airlied@redhat.com>