Add yielding utility calls

utils.hpp provides a bunch of blocking D-Bus calls that are used
liberally in the ipmi handlers. By adding a yielding option that takes
the ipmi::Context::ptr, this can easily turn all the blocking calls into
yielding calls as the handlers get rewritten.

Tested: Used the upcoming modification of XYZ call:
    Before:
       ipmitool get session info
    After:
       ipmitool get session info

Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
Change-Id: Ia537eeda060ea8e56b94b99ccb46b05f18372589
diff --git a/softoff/Makefile.am b/softoff/Makefile.am
index 00f78a5..ec938a3 100644
--- a/softoff/Makefile.am
+++ b/softoff/Makefile.am
@@ -23,8 +23,16 @@
 	$(SDBUSPLUS_LIBS) \
 	$(SDEVENTPLUS_LIBS) \
 	$(PHOSPHOR_LOGGING_LIBS) \
+	-lboost_coroutine \
 	$(PHOSPHOR_DBUS_INTERFACES_LIBS)
 phosphor_softpoweroff_CXXFLAGS = \
+	-flto \
+	-Wno-psabi \
+	-DBOOST_ERROR_CODE_HEADER_ONLY \
+	-DBOOST_SYSTEM_NO_DEPRECATED \
+	-DBOOST_COROUTINES_NO_DEPRECATION_WARNING \
+	-DBOOST_ASIO_DISABLE_THREADS \
+	-DBOOST_ALL_NO_LIB
 	$(SYSTEMD_CFLAGS) \
 	$(SDBUSPLUS_CFLAGS) \
 	$(SDEVENTPLUS_CFLAGS) \