3ca06e0e94
This is in preparation for gfx900, which uses 64-bit doorbells. We
maintain the same number of doorbells per process by making the
doorbell page size bigger.
KFD will need to implement the same rule.
Change-Id: I3c4110869b191b83943b5a390a48edfc94d941d8
[ROCm/ROCR-Runtime commit: 48207af92a]