mt76: add mt76x2_common to mt76x2-common module

Move core related code shared between mt76x2 and mt76x2u in
mt76x2-common module

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
5 files changed