MAINTAINERS: Add IIO include files

Files under include/linux/iio were not reported as part
of the IIO subsystem.

Reported-by: Cristina Ciocan <[email protected]>
Signed-off-by: Daniel Baluta <[email protected]>
Reviewed-by: Jingoo Han <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

Author: Daniel Baluta

MAINTAINERS

@@ -4707,6 +4707,7 @@ L:	[email protected]
 S:	Maintained
 F:	drivers/iio/
 F:	drivers/staging/iio/
+F:	include/linux/iio/
 
 IKANOS/ADI EAGLE ADSL USB DRIVER
 M:	Matthieu Castet <[email protected]>