mmc: sdhci: move broken voltage quirk handling to sdhci_setup_cfg()

If CONFIG_BLK is enabled, add_sdhci() is never called.  Move this
quirk handling to sdhci_setup_cfg(), which is now the central place
for hardware capability checks.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>