drm/amdgpu: Modify the argument of emit_ib interface

use the point of struct amdgpu_job as the function
argument instand of vmid, so the other members of
struct amdgpu_job can be visit in emit_ib function.

v2: add a wrapper for getting the VMID
    add the job before the ib on the parameter list.
v3: refine the wrapper name

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_job.h

@@ -33,6 +33,8 @@
 #define to_amdgpu_job(sched_job)		\
 		container_of((sched_job), struct amdgpu_job, base)
 
+#define AMDGPU_JOB_GET_VMID(job) ((job) ? (job)->vmid : 0)
+
 struct amdgpu_fence;
 
 struct amdgpu_job {