drm/amdgpu: add amdgpu_bo_param

amdgpu_bo_create has too many parameters, and used in
too many places. Collect them to one structure.

Signed-off-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Junwei Zhang <Jerry.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>