gpio: rename gpio_chip_hwgpio() to gpiod_hwgpio()

gpio: rename gpio_chip_hwgpio() to gpiod_hwgpio()

This function takes a GPIO descriptor as first argument. Make its naming
consistent with the rest of the GPIO codebase and use the gpiod_ prefix.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andrew Jeffery <andrew@codeconstruct.com.au>
Link: https://lore.kernel.org/r/20251016-aspeed-gpiolib-include-v1-1-31201c06d124@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>