Entity-Manager: Delete unused define

This define was removed in patch 28633.

(From meta-phosphor rev: bfe856956e8c4fb6100dcd291275a1c1d7ee0974)

Change-Id: I78007656a8ae4ce6f5e69c46a4e92d7c0226ee86
Signed-off-by: James Feist <james.feist@linux.intel.com>
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
diff --git a/meta-phosphor/recipes-phosphor/configuration/entity-manager_git.bb b/meta-phosphor/recipes-phosphor/configuration/entity-manager_git.bb
index 50ab0a4..19b5aed 100644
--- a/meta-phosphor/recipes-phosphor/configuration/entity-manager_git.bb
+++ b/meta-phosphor/recipes-phosphor/configuration/entity-manager_git.bb
@@ -21,5 +21,5 @@
 S = "${WORKDIR}/git/"
 inherit cmake systemd
 
-EXTRA_OECMAKE = "-DYOCTO=1 -DUSE_OVERLAYS=0"
+EXTRA_OECMAKE = "-DYOCTO=1"