IPMIFruArea: move source into separate fru_area.cpp

Move the implementation of the class into its own source file.

Change-Id: I02d941dd8173f0cede8cdfe8af1fdc5f5418abb4
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/Makefile.am b/Makefile.am
index 5862009..41daebb 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -17,6 +17,7 @@
 lib_LTLIBRARIES = libwritefrudata.la
 libwritefrudata_la_SOURCES = frup.cpp \
 	fru-gen.cpp \
+	fru_area.cpp \
 	writefrudata.cpp \
 	extra-properties-gen.cpp
 libwritefrudata_la_LDFLAGS = $(SYSTEMD_LIBS) \