[media] media: rc: nuvoton: simplify a few functions

Simplify a few functions.

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