Nomination of amdgpu fixes for stable backport

Hi stable kernel maintainers,

please squash these amdgpu fixes together and backport them to all applicable stable branches:

15e6b76880e65be24250e30986084b5569b7a06f "drm/amdgpu: Warn and update pin_size values when destroying a pinned BO" 456607d816d89a442a3d5ec98b02c8bc950b5228 "drm/amdgpu: Don't warn on destroying a pinned BO"

(These depend on commits a5ccfe5c20740f2fbf00291490cdf8d2373ec255 and ddc21af4d0f37f42b33c54cb69b215997fe5b082, which already have Cc: stable)