wifi: mt76: mt7996: adjust HW capabilities for mt7990

This is a preliminary patch to support mt7990 chipset.

Co-developed-by: Howard Hsu <howard-yh.hsu@mediatek.com>
Signed-off-by: Howard Hsu <howard-yh.hsu@mediatek.com>
Co-developed-by: Shayne Chen <shayne.chen@mediatek.com>
Signed-off-by: Shayne Chen <shayne.chen@mediatek.com>
Signed-off-by: Peter Chiu <chui-hao.chiu@mediatek.com>
Link: https://patch.msgid.link/20250409140750.724437-8-shayne.chen@mediatek.com


Signed-off-by: Felix Fietkau <nbd@nbd.name>