SN65DSI86 MIPI DSI to eDP bridge driver

Required properties:
- compatible : should be "ti,sn65dsi86".
- reg : i2c regmap address
- ti,enable-gpio : GPIO for enabling DS90UH949 chip
- ti,pll-refclk-cfg : Register value to control DP PLL clock source and frequency

Optional properties:
- ti,disable-assr : Disable ASSR (Alternate Scrambler Seed Reset)
- ti,dp-ssc-cfg : Register value to configure SSC (Spread Spectrum Clock)

Examples:
        i2c@3160000 {
                sn65dsi86@2d {
                        compatible = "ti,sn65dsi86";
                        reg = <0x2d>;
                        status = "okay";
                        ti,enable-gpio = <&tegra_main_gpio TEGRA_MAIN_GPIO(O, 1) 0>;
                        ti,pll-refclk-cfg = <0x4>;
                        ti,disable-assr = <1>;
                        ti,dp-ssc-cfg = <0x30>;
                };

}