mfd: tps65217: Add support for IRQs

Add support for handling IRQs: power button, AC and USB power state
changes. Mask and interrupt bits are shared within one register, which
prevents us to use regmap_irq implementation. New irq_domain is created in
order to add interrupt handling for each tps65217's subsystem. IRQ
resources have been added for charger subsystem to be able to notify about
AC and USB state changes.

Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>