Input: twl4030-pwrbutton - add missing of.h include

The driver is using of_match_ptr() and therefore needs to include
of.h header.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220927052217.2784593-1-dmitry.torokhov@gmail.com


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>