clk: rockchip: fix the clk config to support module build

clk: rockchip: fix the clk config to support module build

use CONFIG_COMMON_CLK_ROCKCHIP for Rk common clk drivers.
use CONFIG_CLK_RKXX for Rk soc clk driver.
Mark CONFIG_CLK_RK3399 to "tristate",
to support building Rk3399 SoC clock driver as module.

Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20200914022304.23908-1-zhangqing@rock-chips.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>