pps: clients: gpio: Use struct device pointer directly

In most parts of the code the platform device is not used.
Use struct device pointer directly to reduce code size and
increase readability.

Acked-by: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210318130321.24227-6-andriy.shevchenko@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>