style: function names should be lower camel

Fix function names to be lower camel.

Change-Id: I145e1f4c03d7740bc1525dcffbdce2f78fd61075
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/pid/builder.hpp b/pid/builder.hpp
index 8891531..2b28663 100644
--- a/pid/builder.hpp
+++ b/pid/builder.hpp
@@ -8,6 +8,6 @@
 #include <unordered_map>
 
 std::unordered_map<int64_t, std::unique_ptr<PIDZone>>
-    BuildZones(std::map<int64_t, PIDConf>& zonePids,
+    buildZones(std::map<int64_t, PIDConf>& zonePids,
                std::map<int64_t, struct ZoneConfig>& zoneConfigs,
                SensorManager& mgr, sdbusplus::bus::bus& modeControlBus);