spmi: pmic-arb: add support for irq_get_irqchip_state

Reviewed-by: Andy Gross <agross@codeaurora.org>
Signed-off-by: Courtney Cavin <courtney.cavin@sonymobile.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Tested-by: Tim Bird <tim.bird@sonymobile.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>