Revert "Delete Essential overlay, Essential PH-1 already has a proper vendor overlay"

This reverts commit 8d41bcf461e2775e3da06d65cb78722008de64c2.
diff --git a/overlay.mk b/overlay.mk
index e3091c8..aaf3c59 100644
--- a/overlay.mk
+++ b/overlay.mk
@@ -6,6 +6,7 @@
 	treble-overlay-lg-g7 \
 	treble-overlay-NavBar \
 	treble-overlay-NightMode \
+	treble-overlay-Essential_PH1 \
 	treble-overlay-Telephony-LTE \
 	treble-overlay-sharp-s2 \
 	treble-overlay-sharp-s2-los \