pinctrl: baytrail: Simplify code with cleanup helpers

Use macros defined in linux/cleanup.h to automate resource lifetime
control in the driver.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>