[coreboot] v2[PATCH]RCA RM4100 irq routing fixes

[joe at smittys.pointclark.net]

Quoting Uwe Hermann <uwe at hermann-uwe.de>:

>
> Hm, looks ok, but where did the first version come from and why was it
> different to this one?
Another 82801DB board. I appeared to make more sense at the time???
> Did you check that not only EHCI works fine now,
> but also that the rest of the devices _continue_ to work as expected?
Yes. I triple checked everything.
>
> Please also re-add the comments if possible to make the code easier to read.
Done.

r3193

Thanks - Joe