The Marvell Armada 38x SoC's SDHCI interface is capable of using 1.8v voltage,
needed for driving "UHS-I" SD cards at their full speed. It is not, however,
possible on the DB board. Due to physical connectivity connector supply is tied
to 3v and any attempt of changing voltage in order to operate in the fastest UHS
modes fails.

This patch enables equivalent SDHCI quirk in order to adjust controller
operation to system capabilities.
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lkml.kernel.org/r/1415980652-7429-3-git-send-email-mw@semihalf.comSigned-off-by: Jason Cooper <jason@lakedaemon.net>