mmc: sdhci: Disable 1.8v modes (HS200/HS400/UHS) if controller can't support 1.8v

The SDHCI controller in a SoC might support HS200/HS400 (indicated
using mmc-hs200-1_8v/mmc-hs400-1_8v dt property), but if the board is
modeled such that the IO lines are not connected to 1.8v then
HS200/HS400 cannot be supported. Disable HS200/HS400 if the board
does not have 1.8v connected to the IO lines. Also Disable DDR/UHS in 1.8v
if the IO lines are not connected to 1.8v.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>