drm/amdgpu: Use version to figure out harvest info

IP tables with version <=2 may use harvest bit. For version 3 and above,
harvest bit is not applicable, instead uses harvest table. Fix the
logic accordingly.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>