In preparation for Device Tree enablement all IRQ controllers
should control their own IRQ domain. This patch provides just
that for the tc3589x GPIO expander.

CC: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>