i2c: exynos5: always enable HSI2C

All Exynos5 platforms have HSI2C controllers and are needed by
various IPs connected to the boards based on these SoCs. Thus
select this by default for Exynos5 platforms.

Signed-off-by: Sachin Kamat <sachin.kamat@samsung.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>