Add nlohmann-json Dependency for Serialization

Added the nlohmann-json dependency to the phosphor-dump-manager for
serialization purposes. This library will be used to handle JSON
serialization and deserialization of dump entry attributes.

Tests:
- Verified build process with the new dependency.

Change-Id: If3b58be7053741afcd8d39d8b09bb66fed31202c
Signed-off-by: Dhruvaraj Subhashchandran <dhruvaraj@in.ibm.com>
diff --git a/meson.build b/meson.build
index 6bc8f03..b80beec 100644
--- a/meson.build
+++ b/meson.build
@@ -32,6 +32,9 @@
 phosphor_dbus_interfaces_dep = dependency('phosphor-dbus-interfaces')
 phosphor_logging_dep = dependency('phosphor-logging')
 
+# nlohmann-json dependency
+nlohmann_json_dep = dependency('nlohmann_json', include_type: 'system')
+
 # Get Cereal dependency.
 cereal_dep = dependency('cereal', required: false)
 has_cereal = cpp.has_header_symbol(
@@ -211,6 +214,7 @@
         sdeventplus_dep,
         phosphor_logging_dep,
         cereal_dep,
+        nlohmann_json_dep,
     ]
 
 phosphor_dump_manager_install = true