pinctrl: qcom: spmi-mpp: add support for hierarchical IRQ chip

pinctrl: qcom: spmi-mpp: add support for hierarchical IRQ chip

spmi-mpp did not have any irqchip support so consumers of this in
device tree would need to call gpio[d]_to_irq() in order to get the
proper IRQ on the underlying PMIC. IRQ chips in device tree should be
usable from the start without the consumer having to make an additional
call to get the proper IRQ on the parent. This patch adds hierarchical
IRQ chip support to the spmi-mpp code to correct this issue.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211008012524.481877-17-dmitry.baryshkov@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>