mfd: ab8500: Pass AB8500 IRQ to debugfs code by resource

The AB8500 debug code which was merged in parallell with the
multiplatform work incidentally introduced a new instance using
the <mach/irqs.h> header which is now deleted, causing this
build regression:

drivers/mfd/ab8500-debugfs.c:95:23:
fatal error: mach/irqs.h: No such file or directory
compilation terminated.
make[4]: *** [drivers/mfd/ab8500-debugfs.o] Error 1

The code most certainly never worked with device tree either
since that does not rely on this kind of hard-coded interrupt
numbers.

Fix the problem at the root by passing it as a named resource
from the ab8500-core driver. Use an untyped resource to
stop the MFD core from remapping this IRQ relative to the
AB8500 irqdomain.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>