Add support for peer-to-peer communication among AMD GPUs over PCIe
bus. Support REQUIRES enablement of config HSA_AMD_P2P.
Signed-off-by: NRamesh Errabolu <Ramesh.Errabolu@amd.com>
Reviewed-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>