meta-phosphor: Add nholmann JSON dependency

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: Idf21b0b6ff6efd33ca4e566128d4db751be388f9
diff --git a/recipes-phosphor/leds/phosphor-led-manager_git.bb b/recipes-phosphor/leds/phosphor-led-manager_git.bb
index 9fdeea0..9b116d5 100644
--- a/recipes-phosphor/leds/phosphor-led-manager_git.bb
+++ b/recipes-phosphor/leds/phosphor-led-manager_git.bb
@@ -27,6 +27,7 @@
 DEPENDS += "sdbusplus ${PYTHON_PN}-sdbus++-native"
 DEPENDS += "systemd"
 DEPENDS += "phosphor-logging"
+DEPENDS += "nlohmann-json"
 
 DEPENDS += "virtual/${PN}-config-native"