sensors/zones: place in namespace and cleanup

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I527dbc8477a232945f696227a7b0b2adbee45175
diff --git a/pid/thermalcontroller.cpp b/pid/thermalcontroller.cpp
index 5a5b9cc..35dcd15 100644
--- a/pid/thermalcontroller.cpp
+++ b/pid/thermalcontroller.cpp
@@ -22,6 +22,9 @@
 
 #include <algorithm>
 
+namespace pid_control
+{
+
 ThermalType getThermalType(const std::string& typeString)
 {
     /* Currently it only supports the two types. */
@@ -106,3 +109,5 @@
 
     return;
 }
+
+} // namespace pid_control