Currently if you don't specify a match callback for your irq_host it's
assumed you match everything. This is a kind of opt-out approach, and
turns out to be the exception rather than the rule.

So change the semantics to be opt-in, ie. you don't match anything unless
you provide a match callback.  This in itself isn't very useful, but will
allow us to provide a default match implementation in a subsequent patch.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The majority of irq_host implementations (3 out of 4) are associated
with a device_node, and need to stash it somewhere. Rather than having
it somewhere different for each host, add an optional device_node pointer
to the irq_host structure.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This patch creates Celleb platform dependent files to support interrupts.
Signed-off-by: NKou Ishizaki <kou.ishizaki@toshiba.co.jp>
Acked-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>