i2c: sh_mobile: Document SoC-specific bindings

Explicitly list the various SoC-specific compatible properties.
This allows checkpatch to validate DTSes.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt

@@ -2,6 +2,15 @@ Device tree configuration for Renesas IIC (sh_mobile) driver
 
 Required properties:
 - compatible      : "renesas,iic-<soctype>". "renesas,rmobile-iic" as fallback
+		     Examples with soctypes are:
+			- "renesas,iic-r8a73a4" (R-Mobile APE6)
+			- "renesas,iic-r8a7740" (R-Mobile A1)
+			- "renesas,iic-r8a7790" (R-Car H2)
+			- "renesas,iic-r8a7791" (R-Car M2-W)
+			- "renesas,iic-r8a7792" (R-Car V2H)
+			- "renesas,iic-r8a7793" (R-Car M2-N)
+			- "renesas,iic-r8a7794" (R-Car E2)
+			- "renesas,iic-sh73a0" (SH-Mobile AG5)
 - reg             : address start and address range size of device
 - interrupts      : interrupt of device
 - clocks          : clock for device