gpio: spacemit-k1: Add set_config callback support

gpio: spacemit-k1: Add set_config callback support

Assign gpiochip_generic_config() to the set_config() callback to support
pin configuration through the GPIO subsystem. This allows users to
configure GPIO pin attributes like pull-up/down when specifying a GPIO
line in the Device Tree.

Signed-off-by: Junhui Liu <junhui.liu@pigmoral.tech>
Reviewed-by: Anand Moon <linux.amoon@gmail.com>
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Reviewed-by: Yixun Lan <dlan@kernel.org>
Signed-off-by: Linus Walleij <linusw@kernel.org>