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/Makefile.am b/Makefile.am
index c1a90ed..1e01319 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -3,6 +3,7 @@
 noinst_LTLIBRARIES = libpower.la
 libpower_la_LDFLAGS = -static
 libpower_la_LIBADD = \
+	-lstdc++fs \
 	$(PHOSPHOR_LOGGING_LIBS) \
 	$(SDBUSPLUS_LIBS) \
 	$(PHOSPHOR_DBUS_INTERFACES_LIBS)