[PATCH] ppc: Disable IRQ probe on ppc

[PATCH] ppc: Disable IRQ probe on ppc

The current "generic" implementation of IRQ probing isn't well suited
for ppc in it's current form, and causes issues with yenta_socket
(and possibly others) on pmac laptops. We didn't have a probe implementation
in the past, we probably don't need one anyway, so for now, the fix is to
make this optional and enable it on x86 and x86_64 but not ppc and ppc64
(the 4 archs to use the generic IRQ code).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>