configure: qemu-ga: report MSI install support in summary

Currently we need to examine config-host.mak to determine whether
options/probes for MSI package generation had desired result. Report
this more prominently in ./configure summary as we do with other
guest agent configure options.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
diff --git a/configure b/configure
index 9d24d59..86a38fe 100755
--- a/configure
+++ b/configure
@@ -4577,6 +4577,7 @@
 echo "build guest agent $guest_agent"
 echo "QGA VSS support   $guest_agent_with_vss"
 echo "QGA w32 disk info $guest_agent_ntddscsi"
+echo "QGA MSI support   $guest_agent_msi"
 echo "seccomp support   $seccomp"
 echo "coroutine backend $coroutine"
 echo "coroutine pool    $coroutine_pool"