amdgpu 32-bit arm warnings

[Dave Airlie]

  CC [M]  drivers/gpu/drm/amd/amdgpu/amdgpu_cs.o
/home/airlied/devel/kernel/drm-next/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c:
In function ‘amdgpu_cs_parser_init’:
/home/airlied/devel/kernel/drm-next/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c:211:21:
warning: cast to pointer from integer of different size
[-Wint-to-pointer-cast]
  chunk_array_user = (uint64_t __user *)(cs->in.chunks);
                     ^
/home/airlied/devel/kernel/drm-next/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c:231:15:
warning: cast to pointer from integer of different size
[-Wint-to-pointer-cast]
   chunk_ptr = (void __user *)chunk_array[i];
               ^
/home/airlied/devel/kernel/drm-next/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c:241:11:
warning: cast to pointer from integer of different size
[-Wint-to-pointer-cast]
   cdata = (void __user *)user_chunk.chunk_data;
           ^

Dave.