build: Add wrapfiles for dependencies

- Update meson.build and add wrapfiles so that all dependencies are
  handled as subprojects.

- This allows builds completely outside of bitbake or an SDK.
  refer: https://gerrit.openbmc-project.xyz/c/openbmc/phosphor-virtual-sensor/+/42349

Tested: built ledManager repo successfully using `meson build`.

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: I35db603d4aa9c2eee41c3cfb27eba6953950fe44
diff --git a/meson.build b/meson.build
index 387c469..f0c7d11 100644
--- a/meson.build
+++ b/meson.build
@@ -38,11 +38,27 @@
     )
 endif
 
-sdeventplus = dependency('sdeventplus')
-phosphorlogging = dependency('phosphor-logging')
-phosphordbusinterfaces = dependency('phosphor-dbus-interfaces')
-gtest = dependency('gtest', main: true, disabler: true, required: true)
-gmock = dependency('gmock', disabler: true, required: true)
+sdeventplus_dep = dependency(
+    'sdeventplus',
+    fallback: [
+        'sdeventplus',
+        'sdeventplus_dep'
+    ],
+)
+phosphor_logging_dep = dependency(
+    'phosphor-logging',
+    fallback: [
+        'phosphor-logging',
+        'phosphor_logging_dep'
+    ],
+)
+phosphor_dbus_interfaces_dep = dependency(
+    'phosphor-dbus-interfaces',
+    fallback: [
+        'phosphor-dbus-interfaces',
+        'phosphor_dbus_interfaces_dep'
+    ],
+)
 prog_python = find_program('python3', required: true)
 realpath_prog = find_program('realpath')
 
@@ -97,9 +113,9 @@
 
 deps = [
     sdbusplus_dep,
-    sdeventplus,
-    phosphorlogging,
-    phosphordbusinterfaces,
+    sdeventplus_dep,
+    phosphor_logging_dep,
+    phosphor_dbus_interfaces_dep,
     nlohmann_json
 ]