dt-bindings: i2c: i2c-rk3x: Add compatible string for RK3506

The i2c controller in the RK3506 is compatible to the variant first found
in the RK3399 SoC, so add the RK3506 to that variant list.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20251021222853.193224-1-heiko@sntech.de
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>

Author: mmind

Documentation/devicetree/bindings/i2c/i2c-rk3x.yaml

@@ -37,6 +37,7 @@ properties:
               - rockchip,px30-i2c
               - rockchip,rk3308-i2c
               - rockchip,rk3328-i2c
+              - rockchip,rk3506-i2c
               - rockchip,rk3528-i2c
               - rockchip,rk3562-i2c
               - rockchip,rk3568-i2c