clk: samsung: s5pv210: Remove legacy board support

Since there is no more support for board files, this patch removes
legacy non-DT support from the clock driver as well, including
unnecessary clkdev aliases.

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