platform/x86: intel-hid: do not set parents of input devices explicitly

devm_input_allocate_device() already causes the supplied struct device
to be set as the parent of the input device, so doing it again is
redundant.

Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-and-tested-by: Alex Hung <alex.hung@canonical.com>