Add UCD90160 class

This class represents the UCD90160 power sequencer
chip, and provides the ability to check that chip for
voltage and PGOOD faults.

This commit just adds function stubs.

Change-Id: Iec6e83e9bcddbd476bdd86a887db08f5875f11cd
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/power-sequencer/types.hpp b/power-sequencer/types.hpp
new file mode 100644
index 0000000..aac6c36
--- /dev/null
+++ b/power-sequencer/types.hpp
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <map>
+#include <string>
+#include <tuple>
+
+namespace witherspoon
+{
+namespace power
+{
+namespace ucd90160
+{
+
+constexpr auto pathField = 0;
+
+//Future commits will add more entries
+using DeviceDefinition = std::tuple<std::string>;
+
+//Maps a device instance to its definition
+using DeviceMap = std::map<size_t, DeviceDefinition>;
+
+}
+}
+}