clk: samsung: exynos5410: Add I2C, HSI2C and RTC clocks

Add clocks for I2C, USI (HSI2C) and RTC to the Exynos5410 clock driver.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>