[U-Boot] [U-Boot, 1/6] rockchip: clk: Add mac clock set for rk3399

[Philipp Tomsich]

> Assuming mac_clk is fed by an external clock, set clk_rmii_src
> clock select control register from IO for rgmii interface.
> 
> Signed-off-by: David Wu <david.wu at rock-chips.com>
> Acked-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
> ---
> 
>  drivers/clk/rockchip/clk_rk3399.c | 21 +++++++++++++++++++--
>  1 file changed, 19 insertions(+), 2 deletions(-)
> 

Reviewed-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>