clk: rockchip: fix incorrect rk3399 spdif-DPTX divider bits

The CLKSEL_CON32 bit_0 is controlled for spdif_8ch, not spdif_rec_dptx,
it should be bit_8, let's fix it.

Fixes: 11551005

 ("clk: rockchip: add clock controller for the RK3399")
Reported-by: Chris Zhong <zyw@rock-chips.com>
Tested-by: Chris Zhong <zyw@rock-chips.com>
Signed-off-by: Xing Zheng <zhengxing@rock-chips.com>
Cc: stable@vger.kernel.org
Signed-off-by: Heiko Stuebner <heiko@sntech.de>