Add fmtlib for phosphor-debug-collector

Call fmtlib to get additional information from journal.

Tested: built phosphor-debug-collector successfully
        and Unit Test passes.

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: Ibe65637a0b29b76269fb4bc3f498438901c9306a
diff --git a/subprojects/fmt.wrap b/subprojects/fmt.wrap
new file mode 100644
index 0000000..6847ae5
--- /dev/null
+++ b/subprojects/fmt.wrap
@@ -0,0 +1,3 @@
+[wrap-git]
+url = https://github.com/fmtlib/fmt
+revision = HEAD