Any of the following devices connected to I2C ch4 of the Salvator-X(S)
boards will operate at 400 kHz:
    PCA9654, 9FGV0841, ADV7482WBBCZ, MAX9611, 5P49V5923, 5P49V6901A
This patch updates the clock frequency to 400 KHz.
Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
[wsa: squashed commits into one]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
 };
 
 &i2c4 {
+       clock-frequency = <400000>;
+
        versaclock5: clock-generator@6a {
                compatible = "idt,5p49v5923";
                reg = <0x6a>;
 
 };
 
 &i2c4 {
+       clock-frequency = <400000>;
+
        versaclock6: clock-generator@6a {
                compatible = "idt,5p49v6901";
                reg = <0x6a>;