CMakeProject: Remove a few unneded declarations

Change-Id: Ida5afcfb502756c45b58ab6600b2ff98329139dc
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/cmakeprojectmanager/builddirreader.h

@@ -38,13 +38,6 @@
 
 namespace CppTools { class ProjectPartBuilder; }
 
-namespace ProjectExplorer {
-class IOutputParser;
-class Kit;
-} // ProjectExplorer
-
-namespace Utils { class QtcProcess; }
-
 namespace CMakeProjectManager {
 namespace Internal {