Conform regulator methods to acronym conventions

Change regulator class methods to conform to OpenBMC capitalization
conventions for acronyms.

Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: I1eb5202685796cbc2d45cb6368ee4dbd4706e504
diff --git a/phosphor-regulators/src/rail.hpp b/phosphor-regulators/src/rail.hpp
index 3fa516b..f825863 100644
--- a/phosphor-regulators/src/rail.hpp
+++ b/phosphor-regulators/src/rail.hpp
@@ -57,7 +57,7 @@
      *
      * @return rail ID
      */
-    const std::string& getId() const
+    const std::string& getID() const
     {
         return id;
     }