drm/amdgpu: query core refclk from bios for smu v13

The smu_info structrue for smu v13 is changed that
core_refclk in v31 strucuture is not correct for
smu v13_0_0

Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Likun Gao <Likun.Gao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>