Remove onRegistration from header.

This is now an implementation detail of registerAsServiceInternal.

Bug: 36424585
Test: build (nothing references this)
Change-Id: I181f5df5bc84ce3a9afb27b79c09bbb0afb75dc6
diff --git a/transport/include/hidl/ServiceManagement.h b/transport/include/hidl/ServiceManagement.h
index ce98f87..a962034 100644
--- a/transport/include/hidl/ServiceManagement.h
+++ b/transport/include/hidl/ServiceManagement.h
@@ -41,11 +41,6 @@
 namespace hardware {
 
 namespace details {
-// deprecated
-// e.x.: android.hardware.foo@1.0, IFoo, default
-void onRegistration(const std::string &packageName,
-                    const std::string &interfaceName,
-                    const std::string &instanceName);
 
 // Will not attempt to start a lazy HAL
 // e.x.: android.hardware.foo@1.0::IFoo, default