mt76x0: usb: move mt76x0u_tx_prepare_skb in usb.c

Move mt76x0u_tx_prepare_skb routine in usb module in
order to remove leftover usb dependency from generic code

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
3 files changed