net: dsa: mt7530: move mt7623 settings out off the mt7530

Moving mt7623 logic out off mt7530, is required to make hardware setting
consistent after we introduce phylink to mtk driver.

Fixes: ca366d6c

 ("net: dsa: mt7530: Convert to PHYLINK API")
Reviewed-by: Sean Wang <sean.wang@mediatek.com>
Tested-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: René van Dorst <opensource@vdorst.com>
Tested-by: Frank Wunderlich <frank-w@public-files.de>
Signed-off-by: David S. Miller <davem@davemloft.net>