clk: cs2000: enable clock skipping mode

CLK_IN skipping mode allows the PLL to maintain lock even when the
CLK_IN signal has missing pulses for up to 20 ms (t CS) at a time.
This patch enables it

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>