pinctrl: lynxpoint: Use standard pattern for memory allocation

The pattern
	foo = kmalloc(sizeof(*foo), GFP_KERNEL);
has an advantage when foo type is changed. Since we are planning a such,
better to be prepared by using standard pattern for memory allocation.

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>