dt-bindings: clock: Add watchdog and SSS clock IDs to Exynos5410

Add IDs for watchdog and Security SubSystem to Exynos5410.  Use the same
number as for Exynos5420 just in case in future these drivers were
merged.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>