[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.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>