pinctrl: aw9523: add missing mutex_destroy

Otherwise the mutex remains after a failed kzalloc.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://lore.kernel.org/20241001212724.309320-1-rosenp@gmail.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>