clk: bcm/kona: Remove ccu_list

This list doesn't look to be used. Let's remove it and any
associated code that would be manipulating this list. This also
silences this error:

drivers/clk/bcm/clk-kona-setup.c:24:1: warning: symbol 'ccu_list' was not declared. Should it be static?

Reviewed-by: Alex Elder <elder@linaro.org>
Cc: Tim Kryger <tim.kryger@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>