xf86-video-mga: Add support for a new G200eH3 device

- Added support for the new deviceID for G200eH3
- Added PLL algorithm for the G200eH3
- Removed the bandwidth limitation for the G200eH3

Signed-off-by: Mathieu Larouche <mathieu.larouche@matrox.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>