arm64: dts: rockchip: rename HDMI ref clock to 'ref' on rk3399

The reference clock for the HDMI controller has been renamed to 'ref',
the previous 'vpll' name is only left for compatibility in the driver.
Rename the clock to the new name.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Tested-by: NMichael Riesch <michael.riesch@wolfvision.net>
Link: https://lore.kernel.org/r/20220422072841.2206452-7-s.hauer@pengutronix.deSigned-off-by: NHeiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3399.dtsi

@@ -1907,7 +1907,7 @@
 			 <&cru SCLK_HDMI_CEC>,
 			 <&cru PCLK_VIO_GRF>,
 			 <&cru PLL_VPLL>;
-		clock-names = "iahb", "isfr", "cec", "grf", "vpll";
+		clock-names = "iahb", "isfr", "cec", "grf", "ref";
 		power-domains = <&power RK3399_PD_HDCP>;
 		reg-io-width = <4>;
 		rockchip,grf = <&grf>;