rockchip: sdhci: Fix sdhci mmc driver probe abort

This patch fix mmc driver abort caused by below patch:
3d296365 mmc: sdhci: Add support for sdhci-caps-mask

After the patch sdhci_setup_cfg() access to host->mmc->dev,
so we have to do init before make the call to the function()

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>