Read and apply Archos MAC address for WiFi card

[dm8tbr]

Currently we use the Marvel internal MAC. Archos use their own but they didn't put an ROM next to the NIC but read it from flash.

Using a different MAC address depending on OS can lead to confusion or problems when users e.g. use MAC filtering.

you should find at offset 0x3FC860 a nice struct to read
struct { unsigned int mac_magic; unsigned char mac_address[6]; }

We could read this to a file and apply to the interface before bringing it up or loading it with the module if this is possible.