dsa: change default interface configuration at first install on architectures using DSA driver

[Arınç ÜNAL]

This is the proper way of managing the switch ports and VLANs on the
DSA driver. All of the switch ports must be in the same bridge. The
steps to configuring VLANs on ports and configuring the interfaces are
also a lot similar to with swconfig.

Wireless interfaces are also included in the bridge properly.

Images are in the attachments.
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