supporting more than ttyS*

[Okash Khawaja]

Hi,

The obvious next step is ttyUSB*. What else can we support?

Regarding the user interface, we add a module param which will be a
string like "ttyUSB0". Internally we convert it to dev_t. When the param
is not supplied, we use "ttyS0". Will that be okay?

Finally, what do we do with ser module param? Keep it around for backward
compatibility?

Thanks,
Okash