clk: rockchip: add missing rk3288 npll rate table

The npll on rk3288 is exactly the same pll type as the other 4. Yet it
was missing the link to the rate table, making rate changes impossible.
Change that by setting the table.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Tested-by: Doug Anderson <dianders@chromium.org>
Tested-by: Kever Yang <kever.yang@rock-chips.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>