Documentation: dt: hwmon: Add OF document for LM90

Add OF document for LM90 in Documentation/devicetree/.

[JD: Add this new file to the LM90 MAINTAINERS entry.]

Signed-off-by: Wei Ni <wni@nvidia.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index ffcaf97..0da6957 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5175,6 +5175,7 @@
 L:	lm-sensors@lm-sensors.org
 S:	Maintained
 F:	Documentation/hwmon/lm90
+F:	Documentation/devicetree/bindings/hwmon/lm90.txt
 F:	drivers/hwmon/lm90.c
 
 LM95234 HARDWARE MONITOR DRIVER