Add gold linker support for boot2qt builds

Task-number: QTBUG-73216
Task-number: COIN-326
Change-Id: I1f5b83520f8ad241652b0a34726743a7ecca7307
Reviewed-by: Samuli Piippo <samuli.piippo@qt.io>

src/core/core_common.pri

@@ -17,6 +17,3 @@ CONFIG -= ltcg
 # Chromium requires C++14
 CONFIG += c++14
 
-#QTBUG-73216 ci has to be updated with latest yocto
-boot2qt: CONFIG -= use_gold_linker
-