Revert "gpio: thunderx: Switch to GPIOLIB_IRQCHIP"

Revert "gpio: thunderx: Switch to GPIOLIB_IRQCHIP"

This reverts commit 7b41568c056d1c1b9bfe0d0c954a47dcd17b1d9a because
there are some bugs in this commit, and we don't have a simple way to
fix these bugs. So revert this commit to make the thunderx gpio work
on the stable kernel at least. We will switch to GPIOLIB_IRQCHIP
for thunderx gpio by following patches.

Fixes: 7b41568c056d ("gpio: thunderx: Switch to GPIOLIB_IRQCHIP")
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Link: https://lore.kernel.org/r/20200114082821.14015-2-haokexin@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>