Since we got rid of platform data, the driver may use GPIO descriptor
directly.

Looking deeply to the use of the GPIO pin it looks like it should be
a fixed voltage regulator rather than custom GPIO handling. But this
is out of scope of the change.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>