qt53d: fix install issue with qt5.6

Both plugins `geometryloaders' and `renderplugins' are available since
Qt 5.9.

Fixes:

	>>> qt53d 5.6.3 Installing to target
	cp -dpf /home/gportay/src/buildroot/output/host/arm-buildroot-linux-gnueabihf/sysroot/usr/lib/libQt53D*.so.*
/home/gportay/src/buildroot/output/target/usr/lib
	cp -dpfr /home/gportay/src/buildroot/output/host/arm-buildroot-linux-gnueabihf/sysroot/usr/lib/qt/plugins/geometryloaders
/home/gportay/src/buildroot/output/target/usr/lib/qt/plugins
	cp: cannot stat '/home/gportay/src/buildroot/output/host/arm-buildroot-linux-gnueabihf/sysroot/usr/lib/qt/plugins/geometryloaders': No such file or directory
	package/pkg-generic.mk:310: recipe for target '/home/gportay/src/buildroot/output/build/qt53d-5.6.3/.stamp_target_installed' failed
	make[2]: *** [/home/gportay/src/buildroot/output/build/qt53d-5.6.3/.stamp_target_installed] Error 1

Signed-off-by: Gaël PORTAY <gael.portay@savoirfairelinux.com>
Signed-off-by: Gaël PORTAY &amp;lt;&lt;a href="mailto:gael.portay@savoirfairelinux.com" target="_blank" <rel="noreferrer"&gt;gael.portay@savoirfairelinux.com&lt;/a&gt;&amp;gt;&lt;br>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>