drm/amdgpu: Add debugfs entry for printing VM info

drm/amdgpu: Add debugfs entry for printing VM info

Create new debugfs entry to print memory info using VM buffer
objects.

V2: Added Common function for printing BO info.
    Dump more VM lists for evicted, moved, relocated, invalidated.
    Removed dumping VM mapped BOs.
V3: Fixed coding style comments, renamed print API and variables.
V4: Fixed coding style comments.

Signed-off-by: Mihir Bhogilal Patel <Mihir.Patel@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>