Revert "GFX-3D: Hold the BufferReference of GraphicBuffer in BpGraphicBufferAlloc"

This reverts commit 7a3802e7699164eb7760f354803ab59afbf42eab.

Change-Id: Ie29d5404c23ca8610f5fa3e5916fe1a124956ba0
(cherry picked from commit c50357aeeb5147e411955e5350ed9b40d6b326dc)