dt-bindings: net: dsa: mediatek,mt7530: Minor wording fixes

dt-bindings: net: dsa: mediatek,mt7530: Minor wording fixes

Update the mt7530 binding with some minor updates that make the document
easier to read.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Acked-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://patch.msgid.link/20240624211858.1990601-1-chris.packham@alliedtelesis.co.nz
Signed-off-by: Jakub Kicinski <kuba@kernel.org>