in the ISR (from the ISA "ed" driver's generic 8390 probe routine).
Also, add a big comment describing exactly what we're checking when
probing for the dp8390 (also lifted from the ISA "ed" driver).
The RST check should help weed-out non-matches before they get to the
fairly invasive memory check.
> revision 1.1.2.4
> date: 1997/10/15 01:01:57; author: enami; state: Exp; lines: +10 -8
> Use bus_space_write_1() directly instead of NIC_PUT(), since
> - same io port is accessed by bus_space_read_1() in the same function, and
> - can bypass sc_reg_map[].