clk: hi3798cv200: correct parent mux clock for 'clk_sdio0_ciu'

Other than 'mmc_mux', 'clk_sdio0_ciu' uses a different parent mux clock.
Let's add this mux clock as 'sdio0_mux', and correct the parent of
'clk_sdio0_ciu' to be it.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>