led-manager: add CLI11 option and config loading

To facilitate localized testing of JSON config loading, add an option
that allows the configuration to be directly passed, rather than try to
determine it from entity-manager config off dbus.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I80d7051bf312044c68f44bcdb9ac02364f9abac3
diff --git a/meson.build b/meson.build
index 84cb8dc..3302bc1 100644
--- a/meson.build
+++ b/meson.build
@@ -64,6 +64,15 @@
     )
 endif
 
+if cpp.has_header('CLI/CLI.hpp')
+    CLI11_dep = declare_dependency()
+else
+    CLI11_dep = dependency(
+        'CLI11',
+        fallback: [ 'CLI11', 'CLI11_dep' ],
+    )
+endif
+
 # Get Cereal dependency.
 cereal_dep = dependency('cereal', required: false)
 has_cereal = cpp.has_header_symbol(
@@ -83,12 +92,13 @@
 endif
 
 deps = [
+    CLI11_dep,
+    cereal_dep,
+    nlohmann_json_dep,
+    phosphor_dbus_interfaces_dep,
+    phosphor_logging_dep,
     sdbusplus_dep,
     sdeventplus_dep,
-    phosphor_logging_dep,
-    phosphor_dbus_interfaces_dep,
-    nlohmann_json_dep,
-    cereal_dep,
 ]
 
 subdir('manager')