pinctrl: aw9523: Add proper terminator

The of_device_id array needs to be terminated with a NULL
entry.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202403061147.85XYVsk3-lkp@intel.com/


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240306-fix-aw9523-terminator-v1-1-13f90f87a7f6@linaro.org