meson: add wrap for mapper

The phosphor-objmgr repository, which supplies libmapper, now
compiles using meson.  Add a wrap file for it to allow builds outside
of Yocto or an SDK.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ic0c9fa2880a86116e03c5a26b51de4dd032baf4b
diff --git a/subprojects/phosphor-objmgr.wrap b/subprojects/phosphor-objmgr.wrap
new file mode 100644
index 0000000..6e41898
--- /dev/null
+++ b/subprojects/phosphor-objmgr.wrap
@@ -0,0 +1,6 @@
+[wrap-git]
+url = https://github.com/openbmc/phosphor-objmgr
+revision = HEAD
+
+[provide]
+libmapper = mapper_dep