Remove qmake build files

Removes qmake as a build system for building Qt Creator itself.
Keep them for some tests that are not completely moved to CMake yet.

Change-Id: I846c6ef65626b6dfae6375fdc85d00677aa8c2fb
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/cppcheck/cppcheck.pro

@@ -1,29 +0,0 @@
-include(../../qtcreatorplugin.pri)
-
-SOURCES += \
-    cppcheckdiagnostic.cpp \
-    cppcheckdiagnosticsmodel.cpp \
-    cppcheckdiagnosticview.cpp \
-    cppcheckmanualrundialog.cpp \
-    cppcheckoptions.cpp \
-    cppcheckplugin.cpp \
-    cppcheckrunner.cpp \
-    cppchecktextmark.cpp \
-    cppchecktextmarkmanager.cpp \
-    cppchecktool.cpp \
-    cppchecktrigger.cpp
-
-HEADERS += \
-    cppcheckconstants.h \
-    cppcheckdiagnostic.h \
-    cppcheckdiagnosticmanager.h \
-    cppcheckdiagnosticsmodel.h \
-    cppcheckdiagnosticview.h \
-    cppcheckmanualrundialog.h \
-    cppcheckoptions.h \
-    cppcheckplugin.h \
-    cppcheckrunner.h \
-    cppchecktextmark.h \
-    cppchecktextmarkmanager.h \
-    cppchecktool.h \
-    cppchecktrigger.h

src/plugins/cppcheck/cppcheck_dependencies.pri

@@ -1,9 +0,0 @@
-QTC_PLUGIN_NAME = Cppcheck
-QTC_LIB_DEPENDS += \
-    extensionsystem \
-    utils
-QTC_PLUGIN_DEPENDS += \
-    cppeditor \
-    debugger \
-    projectexplorer \
-    texteditor