Add use of TESTDATA feature to integration tests

Use TESTDATA and QFINDTESTDATA in integration tests. Also remove
unused path defines from unit test .pro files.

Change-Id: I46dc6a96b918e989acf79eb3bd23c53125c7c3d6
Reviewed-by: Michael Goddard <michael.goddard@nokia.com>

tests/auto/unit/qaudiobuffer/qaudiobuffer.pro

@@ -14,4 +14,3 @@ CONFIG   -= app_bundle
 TEMPLATE = app
 
 SOURCES += tst_qaudiobuffer.cpp
-DEFINES += SRCDIR=\\\"$$PWD/\\\"

tests/auto/unit/qaudiodecoder/qaudiodecoder.pro

@@ -19,4 +19,3 @@ include (../qmultimedia_common/mock.pri)
 include (../qmultimedia_common/mockdecoder.pri)
 
 SOURCES += tst_qaudiodecoder.cpp
-DEFINES += SRCDIR=\\\"$$PWD/\\\"

tests/auto/unit/qmediaplaylist/qmediaplaylist.pro

@@ -6,8 +6,6 @@ include (../qmultimedia_common/mockplaylist.pri)
 QT += multimedia-private testlib
 CONFIG += no_private_qt_headers_warning
 
-DEFINES += TESTDATA_DIR=\\\"$$PWD/\\\"
-
 HEADERS += \
     $$QT.multimedia.sources/../plugins/m3u/qm3uhandler.h
 

tests/auto/unit/qmediaplaylist/tst_qmediaplaylist.cpp

@@ -57,10 +57,6 @@
 #include "mockmediaplaylistsourcecontrol.h"
 #include "mockreadonlyplaylistprovider.h"
 
-#ifndef TESTDATA_DIR
-#define TESTDATA_DIR "./"
-#endif
-
 QT_USE_NAMESPACE
 
 class MockReadOnlyPlaylistObject : public QMediaObject