drm/pagemap: Rename drm_pagemap_device_addr to drm_pagemap_addr

Rename this struct to the more generic name drm_pagemap_addr so it can be
used in a broader context, such as DMA mappings of CPU memory.

Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://lore.kernel.org/r/20250805140028.599361-2-francois.dugast@intel.com


Signed-off-by: Francois Dugast <francois.dugast@intel.com>