MAINTAINERS: adjust file entry in TDA1997x MEDIA DRIVER

MAINTAINERS: adjust file entry in TDA1997x MEDIA DRIVER

Commit c423487bf667 ("dt-bindings: media: convert nxp,tda1997x.txt to yaml
format") renames nxp,tda1997x.txt to nxp,tda19971.yaml as part of this
dt-binding conversion, but misses to adjust the file entry in TDA1997x
MEDIA DRIVER.

Adjust the file entry after the conversion.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@redhat.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>