Add include guard to include/linux/platform_data/max197.h to prevent
multiple inclusion.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

The MAX197 is an A/D converter, made by Maxim. This driver currently
supports the MAX197, and MAX199. They are both 8-Channel, Multi-Range,
5V, 12-Bit DAS with 8+4 Bus Interface and Fault Protection.

The available ranges for the MAX197 are {0,-5V} to 5V, and {0,-10V} to
10V, while they are {0,-2V} to 2V, and {0,-4V} to 4V on the MAX199.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>