linux-phytec-ti

MAINTAINERS: Add maintainer for MAX6697, INA209, and INA2XX drivers

I actively maintain those drivers and have hardware available
to test changes, so add me as explicit maintainer.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Jean Delvare <khali@linux-fr.org>