mfd: ab8500: Delete static IRQ resources

The platforms that use the AB8500 define all IRQ resources in the
device tree and they are automatically populated by matching
the .of_compatible string. These static resources are just
surplus baggage these days.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>