pinctrl: intel: Refactor intel_pinctrl_get_soc_data()

Refactor intel_pinctrl_get_soc_data() to drop initial assignment
of the data variable. It's only used in ACPI case and instead
we may always assign it there as the ACPI ID table has the terminator
entry that has driver data set to NULL.

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