dtoverlays: Add an override for imx477 and 378 for higher link freq

The driver can now support a link freq of 900MHz (1.8Gbit/s/lane)
for higher frame rates.

Add an override for "pi5" that changes this link frequency.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

Author: 6by9

arch/arm/boot/dts/overlays/README

@@ -2842,6 +2842,7 @@ Params: rotation                Mounting rotation of the camera sensor (0 or
         sync-sink               Configure as vsync sink
         link-frequency          Allowable link frequency values to use in Hz:
                                 450000000 (default), 453000000, 456000000.
+        pi5                     Sets the CSI2 link frequency to 900MHz.
 
 
 Name:   imx415
@@ -2920,6 +2921,7 @@ Params: rotation                Mounting rotation of the camera sensor (0 or
         sync-sink               Configure as vsync sink
         link-frequency          Allowable link frequency values to use in Hz:
                                 450000000 (default), 453000000, 456000000.
+        pi5                     Sets the CSI2 link frequency to 900MHz
 
 
 Name:   imx500

arch/arm/boot/dts/overlays/imx477_378-overlay.dtsi

@@ -87,6 +87,7 @@
 		       <&cam_node>, "VANA-supply:0=",<&cam0_reg>;
 		always-on = <0>, "+99";
 		link-frequency = <&cam_endpoint>,"link-frequencies#0";
+		pi5 = <&cam_endpoint>, "link-frequencies#0=900000000";
 	};
 };