xpect only USB interrupts working,
pretty much the same as what arch/ppc did.

Also, the flash, nvram, rtc and temp control still have to be wired.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
u“-…” x