[media] media: rc: nuvoton: eliminate member pdev from struct nvt_dev
Member pdev of struct nvt_dev is needed only to access &pdev->dev.
We can get rid of this it by using rdev->dev.parent instead
(both point to the same struct device).
Setting rdev->dev.parent can be removed from the probe function
as this is done by devm_rc_allocate_device now.