drm/i915: Implement fdinfo memory stats printing

Use the newly added drm_print_memory_stats helper to show memory
utilisation of our objects in drm/driver specific fdinfo output.

To collect the stats we walk the per memory regions object lists
and accumulate object size into the respective drm_memory_stats
categories.

v2:
 * Only account against the active region.
 * Use DMA_RESV_USAGE_BOOKKEEP when testing for active. (Tejas)

v3:
 * Update commit text. (Aravind)
 * Update to use memory regions uabi names.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Aravind Iddamsetty <aravind.iddamsetty@intel.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Tejas Upadhyay <tejas.upadhyay@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Aravind Iddamsetty <aravind.iddamsetty@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231107101806.608990-6-tvrtko.ursulin@linux.intel.com