-put all early console / KGDB initialization into 1 exported function
(com_*_attach()) each, dont use global variables anymore
-use the passed tcflag_t for port settings instead of hardwiring 8N1
-at autoconfiguration attach time, decide if the attaching device is
already console / KGDB by comparing bus tag and base addr (cgd's wish)
-export a function "com_is_console()" for use by driver frontends for
this comparision
-delay setting of cn_tab->cn_dev until autoconfiguration attach
to get the minor number right
-delete unused comcnprobe() and comcninit()
d36e668737