clk: rk3399: Enable/Disable the PCIEPHY clk

Enable/Disable the PCIEPHY clk for rk3399.

CLK is clear in both enable and disable functionality.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Suniel Mahesh <sunil@amarulasolutions.com> #roc-rk3399-pc
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>