arm64: dts: imx8mp-phyboard-pollux: Set Video PLL1 frequency to 506.8 MHz

The LVDS panel on this device uses 72.4 MHz pixel clock, set IMX8MP_VIDEO_PLL1
to 72.4 * 7 = 506.8 MHz so the LDB serializer and LCDIFv3 scanout engine can
reach accurate pixel clock of exactly 72.4 MHz.

Without this patch, the Video PLL1 frequency is the default set in imx8mp.dtsi
which is 1039.5 MHz, which divides down to inaccurate pixel clock of 74.25 MHz
which works for this particular panel by sheer chance.

Stop taking that chance and set correct accurate pixel clock frequency instead.

Fixes: 326d86e ("arm64: dts: imx8mp-phyboard-pollux-rdk: add etml panel support")
Reported-by: Isaac Scott <[email protected]>
Signed-off-by: Marek Vasut <[email protected]>
Reviewed-by: Yannic Moog <[email protected]>
Tested-by: Yannic Moog <[email protected]>
Signed-off-by: Shawn Guo <[email protected]>

Author: Marek Vasut

arch/arm64/boot/dts/freescale/imx8mp-phyboard-pollux-rdk.dts

@@ -218,6 +218,18 @@
 	};
 };
 
+&media_blk_ctrl {
+	/*
+	 * The LVDS panel on this device uses 72.4 MHz pixel clock,
+	 * set IMX8MP_VIDEO_PLL1 to 72.4 * 7 = 506.8 MHz so the LDB
+	 * serializer and LCDIFv3 scanout engine can reach accurate
+	 * pixel clock of exactly 72.4 MHz.
+	 */
+	assigned-clock-rates = <500000000>, <200000000>,
+			       <0>, <0>, <500000000>,
+			       <506800000>;
+};
+
 &snvs_pwrkey {
 	status = "okay";
 };