soc: mediatek: mtk-socinfo: Avoid using machine attribute in SoC detection log

The recently introduced SoC attribute info rework avoided modifying the
machine attribut but still used it in the log message on successful SoC
matching. It leads to print a confusing log about a board-related info
(read from devicetree) and not about the matched SoC:
```
mtk-socinfo mtk-socinfo.0.auto: MediaTek MediaTek Genio-510 EVK SoC
detected
```

So, fix the dev_info format to display SoC family and name attribute
instead.
```
mtk-socinfo mtk-socinfo.0.auto: MediaTek Genio 510 (MT8370) SoC detected.
```

Fixes: da77c2d3d06c ("soc: mediatek: mtk-socinfo: Restructure SoC attribute information")
Signed-off-by: Louis-Alexis Eyraud <[e-mail]>
Reviewed-by: Fei Shao <[e-mail]>
Tested-by: Fei Shao <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: AngeloGioacchino Del Regno <[e-mail]>

drivers/soc/mediatek/mtk-socinfo.c

···
 	if (IS_ERR(mtk_socinfop->soc_dev))
 		return PTR_ERR(mtk_socinfop->soc_dev);
 
-	dev_info(mtk_socinfop->dev, "%s %s SoC detected.\n", soc_manufacturer, attrs->machine);
+	dev_info(mtk_socinfop->dev, "%s (%s) SoC detected.\n", attrs->family, attrs->soc_id);
 	return 0;
 }