ARM: dts: imx6: RDU2: assign video PLL as input to LDB

Currently we don't ensure that the LDB is clocked from the video PLL
and relied on the bootloader to do the correct setup. This isn't always
true, in which case we would run with a vastly different video clock
than the desired one. Fix this by assigning the proper parent to the
LDB.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6qdl-zii-rdu2.dtsi

@@ -216,6 +216,13 @@ edp_refclk: edp-refclk {
 	};
 };
 
+&clks {
+	assigned-clocks = <&clks IMX6QDL_CLK_LDB_DI0_SEL>,
+	                  <&clks IMX6QDL_CLK_LDB_DI1_SEL>;
+	assigned-clock-parents = <&clks IMX6QDL_CLK_PLL5_VIDEO_DIV>,
+	                         <&clks IMX6QDL_CLK_PLL5_VIDEO_DIV>;
+};
+
 &cpu0 {
 	fsl,soc-operating-points = <
 		/* ARM kHz  SOC-PU uV */