counter: intel-qep: Use to_pci_dev() helper

Use to_pci_dev() helper instead of container_of(d, struct pci_dev, dev);

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/20210611115558.796338-2-jarkko.nikula@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>