drm/amdgpu: Use drm_print_memory_stats helper from fdinfo

drm/amdgpu: Use drm_print_memory_stats helper from fdinfo

Convert fdinfo memory stats to use the common drm_print_memory_stats
helper.

This achieves alignment with the common keys as documented in
drm-usage-stats.rst, adding specifically drm-total- key the driver was
missing until now.

Additionally I made the code stop skipping total size for objects which
currently do not have a backing store, and I added resident, active and
purgeable reporting.

Legacy keys have been preserved, with the outlook of only potentially
removing only the drm-memory- when the time gets right.

The example output now looks like this:

 pos:	0
 flags:	02100002
 mnt_id:	24
 ino:	1239
 drm-driver:	amdgpu
 drm-client-id:	4
 drm-pdev:	0000:04:00.0
 pasid:	32771
 drm-total-cpu:	0
 drm-shared-cpu:	0
 drm-active-cpu:	0
 drm-resident-cpu:	0
 drm-purgeable-cpu:	0
 drm-total-gtt:	2392 KiB
 drm-shared-gtt:	0
 drm-active-gtt:	0
 drm-resident-gtt:	2392 KiB
 drm-purgeable-gtt:	0
 drm-total-vram:	44564 KiB
 drm-shared-vram:	31952 KiB
 drm-active-vram:	0
 drm-resident-vram:	44564 KiB
 drm-purgeable-vram:	0
 drm-memory-vram:	44564 KiB
 drm-memory-gtt: 	2392 KiB
 drm-memory-cpu: 	0 KiB
 amd-memory-visible-vram:	44564 KiB
 amd-evicted-vram:	0 KiB
 amd-evicted-visible-vram:	0 KiB
 amd-requested-vram:	44564 KiB
 amd-requested-visible-vram:	11952 KiB
 amd-requested-gtt:	2392 KiB
 drm-engine-compute:	46464671 ns

v2:
 * Track purgeable via AMDGPU_GEM_CREATE_DISCARDABLE.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Rob Clark <robdclark@chromium.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>