mt76: allow hw driver code to overwrite wiphy interface_modes

Move wiphy interface_modes configuration in mt76_alloc_device and
mt76_alloc_phy in order to be overwritten by hw specific code
since some drivers do not support all operating modes (mt7921
supports sta only in the current codebase)

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>