Interrupt code update

[Roman Z. <zi...@li...>]

Hi,

> Log message:
>   use general interrupt management code

This was a major surgery, I hoped everything still works as before,
please test it carefully.
Biggest visible difference is a new /proc/interrupts format, which is
now the same as for other ppc machines. Otherwise there is now finally
that annoying "Trying to enable auto-vector" print gone. I left another
print in (last_ipl[x] already set to...), it should only occur rarely
and shouldn't be a problem. I'll remove it later again.

bye, Roman