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/meson.build b/meson.build
index 66b7ca9..666ef06 100644
--- a/meson.build
+++ b/meson.build
@@ -87,7 +87,7 @@
 systemd = dependency('systemd')
 crypto = dependency('libcrypto', version : '>=1.0.2g')
 pam = cpp.find_library('pam', required: true)
-mapper = cpp.find_library('mapper', required: true)
+mapper = dependency('libmapper')
 boost_coroutine = cpp.find_library('boost_coroutine', required: true)
 std_cpp_fs = cpp.find_library('stdc++fs', required: true)
 
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