pinctrl: at91: use devm_kasprintf() to avoid potential leaks (part 2)

pinctrl: at91: use devm_kasprintf() to avoid potential leaks (part 2)

Use devm_kasprintf() instead of kasprintf() to avoid any potential
leaks. At the moment drivers have no remove functionality hence
there is no need for fixes tag.

While at it, switch to use devm_kasprintf_strarray().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20230215134242.37618-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>