ARM: dts: imx6qdl-prti6q.dtsi: Add applicable properties to usdhc3

The usdhc3 interface is connected to a soldered eMMC chip on all boards
that import this dtsi. Adding these properties speeds up the device probe
during boot.

Signed-off-by: Robin van der Gracht <robin@protonic.nl>
Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>