ANDROID: gpiolib: Do not free in pinctrl if pin ranges are not defined

There is a similar check for request, but not in free. This has caused
an imbalace count of request vs. free calls to the pinctrl driver. This
patch is targeted to fix that issue.

Bug: 170496520

Signed-off-by: Edmond Chung <edmondchung@google.com>
Signed-off-by: Andrew Chant <achant@google.com>
Change-Id: Icc9dad21e8036c5cb98627f005e92290335c83fc