amd/amdkfd: sync all devices to wait all processes being evicted

amd/amdkfd: sync all devices to wait all processes being evicted

If there are more than one device doing reset in parallel, the first
device will call kfd_suspend_all_processes() to evict all processes
on all devices, this call takes time to finish. other device will
start reset and recover without waiting. if the process has not been
evicted before doing recover, it will be restored, then caused page
fault.

Signed-off-by: Zhigang Luo <Zhigang.Luo@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>