`lspci` and `lshw` only show driver information for hardware handled by a kernel driver. In your case, the graphics hardware is managed by a X.org driver, not a kernel driver, so the driver doesn’t show up in the output of `lspci` or `lshw`.
The fact that your screen resolution increased is a strong indicator that you succeeded, as is the successful loading of the `sis` module traced in the X.org server logs.