drm/panfrost: Add BO labelling to Panfrost

Functions for labelling UM-exposed an internal BOs are provided. An
example of the latter would be the Perfcnt sample buffer.

This commit is done in preparation of a following one that will allow
UM to set BO labels through a new ioctl().

Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20250520174634.353267-2-adrian.larumbe@collabora.com