Add Vim modelines

Change-Id: I23f30cd9be56089498089f8b12abe3f3e186b525
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/hwmon.hpp b/hwmon.hpp
index 505c625..f41c53e 100644
--- a/hwmon.hpp
+++ b/hwmon.hpp
@@ -21,3 +21,5 @@
 }
 
 #endif
+
+// vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4