doc: devicetree: Fix various typos

Fix spelling typos in Documentation/devicetree/bindings.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/Documentation/devicetree/bindings/regulator/max8997-regulator.txt b/Documentation/devicetree/bindings/regulator/max8997-regulator.txt
index 9fd69a1..9e5e51d 100644
--- a/Documentation/devicetree/bindings/regulator/max8997-regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/max8997-regulator.txt
@@ -28,7 +28,7 @@
     safe operating voltage).
 
     If either of the 'max8997,pmic-buck[1/2/5]-uses-gpio-dvs' optional
-    property is specified, then all the eigth voltage values for the
+    property is specified, then all the eight voltage values for the
     'max8997,pmic-buck[1/2/5]-dvs-voltage' should be specified.
 
 Optional properties: