drm/vmwgfx: Set a unique ID for each submitted command buffer

drm/vmwgfx: Set a unique ID for each submitted command buffer

These IDs are logged by the Hypervisor when debug logging is enabled.
Having the IDs in the log makes it much easier to see when command
buffers start and finish. They can also be used by logging/tracing
in the Guest to help correlate between Guest and Hypervisor logs.

Signed-off-by: Ian Forbes <ian.forbes@broadcom.com>
Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
Link: https://patch.msgid.link/20260109155139.3259493-1-ian.forbes@broadcom.com