gpio: thunderx: Switch to GPIOLIB_IRQCHIP

gpio: thunderx: Switch to GPIOLIB_IRQCHIP

The main parts of this patch are from commit a7fc89f9d5fc ("gpio:
thunderx: Switch to GPIOLIB_IRQCHIP") and patch [1]. And also adjust
thunderx_gpio_child_to_parent_hwirq() and add
thunderx_gpio_populate_parent_alloc_info() to make sure that
the correct hwirq are passed to the parent msi irqdomain.

[1] https://patchwork.ozlabs.org/patch/1210180/

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Link: https://lore.kernel.org/r/20200114082821.14015-5-haokexin@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>