mfd: Correct ro and cd implemantion on DM355

This patch corrects the support for MMCSD card detection
and read only feature for SoC DM355.

EVMDM355_ECP_VA4.pdf, from Spectrum digital, suggests that
Bit 2 and 4 should be checked for card detection. However
on the EVM, bits 1 and 3 gives this status, for MMC/SD
instance 0 and 1 respectively. The pdf also suggests that
Bit 1 and 3 should be checked for write protection. However
on the EVM bits 2 and 4 gives this status.

This document can be downloaded from
http://c6000.spectrumdigital.com/evmdm355/reve/files/EVMDM355_ECP_VA4.pdf



Signed-off-by: Vipin Bhandari <vipin.bhandari@ti.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>