mt76x02: enable support for IBSS and MESH

Since we implement beconing on USB now, similar interfaces should be
supported for USB as are for MMIO. Tested only on IBSS mode and
AP mode (not enabled due to lack of PS buffering).

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>