pinctrl: intel: Move debounce validation out of the lock

There is no need to validate debounce value under the lock.
Move it outside.

It also results in a smaller binary:

  add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-11 (-11)
  Total: Before=15374, After=15363, chg -0.07%

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>