pinctrl: samsung: Add missing initconst annotation

Exynos5433 support has been added in parallel to adding initconst
annotation to most of the init data structures, so add those
annotations also to Exynos5433 structures.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>