media: MAINTAINERS: add entry for NXP TDA1997x driver

Add new MAINTAINERS entry.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
[hans.verkuil@cisco.com: make a proper commit message]
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>