meson: add subproject support

Enable building the repository outside of an OpenBMC Docker container or
SDK by leveraging meson subproject support.  Copy wrap files from
elsewhere in the organization and update the meson dependencies for some
missing dependencies.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I9f2cdc310cbee3fd4ee911cca5e339c4e1ebb94f
diff --git a/subprojects/sdbusplus.wrap b/subprojects/sdbusplus.wrap
new file mode 100644
index 0000000..7b076d0
--- /dev/null
+++ b/subprojects/sdbusplus.wrap
@@ -0,0 +1,6 @@
+[wrap-git]
+url = https://github.com/openbmc/sdbusplus.git
+revision = HEAD
+
+[provide]
+sdbusplus = sdbusplus_dep