clk: rockchip: Fix wrong parent for SDMMC phase clock for rk3228

commit c420c1e4db22 ("clk: rockchip: Prevent calculating mmc phase
if clock rate is zero") catches one gremlin again for clk-rk3228.c
that the parent of SDMMC phase clock should be sclk_sdmmc0, but not
sclk_sdmmc. However, the naming of the sdmmc clocks varies in the
manual with the card clock having the 0 while the hclk is named
without appended 0. So standardize one one format to prevent
confusion, as there also is only one (non-sdio) mmc controller on
the soc.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>