pid/builder: add missing headers

Add missing headers for int64_t, string, vector, etc.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: Iae47813345ee4ed0e01e6a7f5fb12692d9109a81
diff --git a/pid/builder.cpp b/pid/builder.cpp
index 39b29d6..9f27ed4 100644
--- a/pid/builder.cpp
+++ b/pid/builder.cpp
@@ -26,9 +26,12 @@
 
 #include <sdbusplus/bus.hpp>
 
+#include <cstdint>
 #include <iostream>
 #include <memory>
+#include <string>
 #include <unordered_map>
+#include <vector>
 
 namespace pid_control
 {