drm/nouveau/uvmm: Prepare for larger pages

drm/nouveau/uvmm: Prepare for larger pages

Currently memory allocated by VM_BIND uAPI can only have a  granuality
matching PAGE_SIZE (4KiB in common case)

To have a better memory management and to allow big (64KiB) and huge
(2MiB) pages later in the series, we are now passing the page shift all
around the internals of UVMM.

Signed-off-by: Mary Guillemard <mary@mary.zone>
Co-developed-by: Mohamed Ahmed <mohamedahmedegypt2001@gmail.com>
Signed-off-by: Mohamed Ahmed <mohamedahmedegypt2001@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: James Jones <jajones@nvidia.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patch.msgid.link/20251110-nouveau-compv6-v6-1-83b05475f57c@mary.zone