On gfx900 we need 64-bit for all doorbells and SDMA WPTRs. Change-Id: I9b922e16442e967599ae3c928308451d5cc470b3 Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com> [ROCm/ROCR-Runtime commit: d7063dd102]
d7063dd102