drm/xe: Add uapi for dumpable bos

Add the flag XE_VM_BIND_FLAG_DUMPABLE to notify devcoredump that this
mapping should be dumped.

This is not hooked up, but the uapi should be ready before merging.

It's likely easier to dump the contents of the bo's at devcoredump
readout time, so it's better if the bos will stay unmodified after
a hang. The NEEDS_CPU_MAPPING flag is removed as requirement.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240221133024.898315-3-maarten.lankhorst@linux.intel.com