pinctrl: intel: Split intel_config_get() to three functions

Split intel_config_get() to three functions, i.e. intel_config_get() and
two helpers intel_config_get_pull() and intel_config_get_debounce() to be
symmetrical with intel_config_set*().

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