drm/amdkfd: CRIU Implement KFD unpause operation

Introducing UNPAUSE op. After CRIU amdgpu plugin performs a PROCESS_INFO
op the queues will be stay in an evicted state. Once the plugin is done
draining BO contents, it is safe to perform an UNPAUSE op for the queues
to resume.

Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: David Yat Sin <david.yatsin@amd.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>