Debugger: fix metatype declaration macro usage

in places where we do not need it.

Change-Id: Ifb7eba6f46bf79f2cfe968ab8b71cca3a7d51efd
Reviewed-by: hjk <hjk@theqtcompany.com>
Reviewed-by: Ulf Hermann <ulf.hermann@theqtcompany.com>

src/plugins/debugger/cdb/cdbengine.cpp

@@ -76,9 +76,6 @@
 
 #include <cctype>
 
-Q_DECLARE_METATYPE(Debugger::Internal::DisassemblerAgent*)
-Q_DECLARE_METATYPE(Debugger::Internal::MemoryAgent*)
-
 enum { debug = 0 };
 enum { debugLocals = 0 };
 enum { debugSourceMapping = 0 };