drm/amdgpu/sriov:increate mailbox polling timeout

increase timeout to 12 seconds,because there may have multiple
FLR waiting for done, the waiting time of events may be long,
increase to 12s to reduce timeout failure.

Signed-off-by: Horace Chen <horace.chen@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/mxgpu_vi.h b/drivers/gpu/drm/amd/amdgpu/mxgpu_vi.h
index c791d73..f13dc6c 100644
--- a/drivers/gpu/drm/amd/amdgpu/mxgpu_vi.h
+++ b/drivers/gpu/drm/amd/amdgpu/mxgpu_vi.h
@@ -23,7 +23,7 @@
 #ifndef __MXGPU_VI_H__
 #define __MXGPU_VI_H__
 
-#define VI_MAILBOX_TIMEDOUT	5000
+#define VI_MAILBOX_TIMEDOUT	12000
 #define VI_MAILBOX_RESET_TIME	12
 
 /* VI mailbox messages request */