drm/radeon: clarify why we evict vram twice on suspend

Update the comment to explain why we do this.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Alex Deucher 2016-10-10 12:42:33 -04:00
commit ec9aaaff66