Revert "gralloc: Allow legacy devices to use PMEM for ADSP (camera)."

This is obsolete when using the new pmem->ion kernel wrapper.

This reverts commit c65ea89f84e1be60a1d094ff56b666a540b2602a.

Change-Id: Ibf91fefa160e74d93e289d9b6ccbe41e56915647
Merge "Revert "gralloc: Allow legacy devices to use PMEM for ADSP (camera)."" into kk44