This removes the internal functions for assigning IRQ
handlers to each interrupt in favor of using the internal
map iterator in the irq domain code.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>