Out of tree build: Add nlohmann as valijson depend

Valijson requires nlohmann, sometimes we hit a order
issue where json.hpp can't be found, this should fix
it.

Change-Id: I282f292865682c6efdc7db507bdb190f633481c1
Signed-off-by: James Feist <james.feist@linux.intel.com>
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8aeb6d1..cae436c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -110,6 +110,7 @@
     add_dependencies (entity-manager sdbusplus-project)
     add_dependencies (entity-manager valijson)
     add_dependencies (fru-device sdbusplus-project)
+    add_dependencies (valijson nlohmann-json)
 endif ()
 
 set (