ARM: SAMSUNG: Remove legacy clock code

Since S5PV210 now has a complete clock driver using Common Clock
Framework, there is no reason to keep the old code. Remove it together
with the whole legacy Samsung-specific clock framework which no longer
has any users.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>