gpiolib: rework the wrapper around gpio_chip::set_multiple()

Make the existing wrapper around gpio_chip::set_multiple() consistent
with the one for gpio_chip::set(): make it return int, add a lockdep
assertion, warn on missing set callback and move the code a bit for
better readability.

Add return value checks in all call places.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20250220-gpio-set-retval-v2-4-bc4cfd38dae3@linaro.org


Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>