internal modems. Currently detects a USR modem, and a couple Supra
modems... vendor id's for sio capabile cards welcomed...
document new option EXTRA_SIO that will increase sio's internal data
structures to support X more serial ports... these are used by the
PnP part of sio for attaching... If you don't have it specified, it
will default to 2... This is defaulted to 0 if you don't have PnP
compiled into your kernel...
also document that if you set the PnP flags (pnp x flags y) to 0x1 that
the modem will be refused to be recognized by the sio driver... this
is for people that want the traditional isa driver to probe and attach
the modem... (for keeping legacy sio numbering)