linux-firmware commit 808cba84 ("mtk_wed: add firmware for mt7988
Wireless Ethernet Dispatcher") added mt7988_wo_{0,1}.bin in the
'mediatek/mt7988' directory while driver current expects the files in
the 'mediatek' directory.
Change path in the driver header now that the firmware has been added.
Fixes: e2f64db13aa1 ("net: ethernet: mtk_wed: introduce WED support for MT7988")
Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>