gpio: loongson: add more gpio chip support

This patch was to add loongson 2k0500, 2k2000 and 3a5000 gpio chip
driver support and define inten_offset attibute to enable gpio chip
interrupt.

Signed-off-by: Yinbo Zhu <zhuyinbo@loongson.cn>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: loongson: Remove unnecessary .owner

Remove .owner field if calls are used which set it automatically.

./drivers/gpio/gpio-loongson-64bit.c:225:3-8: No need to set .owner here. The core will do it.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=4450
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: loongson: add gpio driver support

The Loongson platforms GPIO controller contains 60 GPIO pins in total,
4 of which are dedicated GPIO pins, and the remaining 56 are reused
with other functions. Each GPIO can set input/output and has the
interrupt capability.

This driver added support for Loongson GPIO controller and support to
use DTS or ACPI to descibe GPIO device resources.

Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Hongchen Zhang <zhanghongchen@loongson.cn>
Signed-off-by: Liu Peibao <liupeibao@loongson.cn>
Signed-off-by: Juxin Gao <gaojuxin@loongson.cn>
Signed-off-by: Yinbo Zhu <zhuyinbo@loongson.cn>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>