fix example installs

Change-Id: I9daec1e1ec1bc163d451ac03685ef6caba7dbde7
Reviewed-by: Yoann Lopes <yoann.lopes@qt.io>

examples/multimedia/spectrum/3rdparty/fftreal/fftreal.pro

@@ -42,3 +42,4 @@ EXAMPLE_FILES = bwins/fftreal.def eabi/fftreal.def readme.txt license.txt
 target.path = $$[QT_INSTALL_EXAMPLES]/multimedia/spectrum
 INSTALLS += target
 
+CONFIG += install_ok  # Do not cargo-cult this!

examples/multimedia/spectrum/app/app.pro

@@ -57,6 +57,8 @@ RESOURCES = spectrum.qrc
 target.path = $$[QT_INSTALL_EXAMPLES]/multimedia/spectrum
 INSTALLS += target
 
+CONFIG += install_ok  # Do not cargo-cult this!
+
 # Deployment
 
 DESTDIR = ..$${spectrum_build_dir}

examples/multimedia/spectrum/spectrum.pro

@@ -10,3 +10,6 @@ SUBDIRS += app
 
 TARGET = spectrum
 
+EXAMPLE_FILES += \
+    README.txt \
+    TODO.txt

examples/multimedia/video/qmlvideo/qmlvideo.pro

@@ -16,3 +16,6 @@ include($$SNIPPETS_PATH/performancemonitor/performancemonitordeclarative.pri)
 target.path = $$[QT_INSTALL_EXAMPLES]/multimedia/video/qmlvideo
 INSTALLS += target
 
+EXAMPLE_FILES += \
+    qmlvideo.png \
+    qmlvideo.svg

examples/multimedia/video/qmlvideofx/qmlvideofx.pro

@@ -19,3 +19,7 @@ OTHER_FILES += \
     android/AndroidManifest.xml
 
 QMAKE_INFO_PLIST = Info.plist
+
+EXAMPLE_FILES += \
+    qmlvideofx.png \
+    qmlvideofx.svg

examples/multimedia/video/video.pro

@@ -2,3 +2,6 @@ TEMPLATE = subdirs
 
 SUBDIRS += qmlvideo qmlvideofx
 
+EXAMPLE_FILES += \
+    qmlvideofilter_opencl \   # FIXME: this one should use a configure check instead
+    snippets