mmc: sdhci: Add Auto CMD Auto Select support

mmc: sdhci: Add Auto CMD Auto Select support

As SD Host Controller Specification v4.10 documents:
Host Controller Version 4.10 defines this "Auto CMD Auto Select" mode.
Selection of Auto CMD depends on setting of CMD23 Enable in the Host
Control 2 register which indicates whether card supports CMD23. If CMD23
Enable =1, Auto CMD23 is used and if CMD23 Enable =0, Auto CMD12 is
used. In case of Version 4.10 or later, use of Auto CMD Auto Select is
recommended rather than use of Auto CMD12 Enable or Auto CMD23
Enable.

This patch add this new mode support.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>