clk: exynos4: Remove unused function

Subsequent to the cleanup in commit 3c70348c

 ("ARM: EXYNOS:
Remove legacy timer initialization code"), this function has no more
users. Hence remove it.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>