meson: adjust nlohmann-json dependency

The meson dependency for nlohmann-json can be simplified quite
a bit from what some repositories are doing.  Use the simplest
form of the dependency and rename the wrap file for consistency.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I51ecfabc37d4023b33b72e558a5a65f97ae303fd
diff --git a/meson.build b/meson.build
index cc34397..7dc8133 100644
--- a/meson.build
+++ b/meson.build
@@ -34,8 +34,7 @@
     i2c = cpp.find_library('i2c')
 endif
 
-nlohmann_json_dep = dependency('nlohmann_json',
-                               fallback: [ 'nlohmann_json', 'nlohmann_json_dep'])
+nlohmann_json_dep = dependency('nlohmann_json', include_type: 'system')
 
 sdbusplus = dependency('sdbusplus', required: false)
 if not sdbusplus.found()