PEL: Create the PLDMInterface class

Create the PLDMInterface class and pass it into the constructor
of the Manager class.  This is done at this level so that it
can be easily mocked for testing.

Add a --enable-dont-send-pels-to-host configure option for systems
that don't need PELs sent to the host.  If this is set, then don't
create and pass in the PLDMInterface class, and then the Manager
class won't create a HostNotifier class to do the sending.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I34059470ee117e65c5c02b684a9d916571135bfd
diff --git a/configure.ac b/configure.ac
index 8481175..657424d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -172,6 +172,13 @@
         AX_PKG_CHECK_MODULES([LIBPLDM], [libpldm])]
 )
 
+AC_ARG_ENABLE([dont-send-pels-to-host],
+              AS_HELP_STRING([--enable-dont-send-pels-to-host],
+                   [Do not send PELs to the host. \
+                    Only applies when PELs are enabled.]),
+    [AX_APPEND_COMPILE_FLAGS([-DDONT_SEND_PELS_TO_HOST])]
+)
+
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_FILES([Makefile test/Makefile phosphor-rsyslog-config/Makefile])
 AC_CONFIG_FILES([phosphor-logging.pc])