arm64: dts: imx8mq: add hdmi phy 27m clock

The i.MX8MQ PLL support hdmi phy 27m as pll reference clock,
so add a fixed clock for it.
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Abel Vesa <abel.vesa@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mq.dtsi

@@ -63,6 +63,13 @@ osc_27m: clock-osc-27m {
 		clock-output-names = "osc_27m";
 	};
 
+	hdmi_phy_27m: clock-hdmi-phy-27m {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+		clock-frequency = <27000000>;
+		clock-output-names = "hdmi_phy_27m";
+	};
+
 	clk_ext1: clock-ext1 {
 		compatible = "fixed-clock";
 		#clock-cells = <0>;