dt-bindings: mfd: syscon: Document Exynos3 and Exynos5433 compatibles

Document Samsung Exynos3 and Exynos5433 compatibles for system
registers.
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

Documentation/devicetree/bindings/mfd/syscon.yaml

@@ -40,8 +40,10 @@ properties:
               - allwinner,sun50i-a64-system-controller
               - microchip,sparx5-cpu-syscon
               - mstar,msc313-pmsleep
+              - samsung,exynos3-sysreg
               - samsung,exynos4-sysreg
               - samsung,exynos5-sysreg
+              - samsung,exynos5433-sysreg
 
           - const: syscon