mmc: unbreak sdhci-esdhc-imx on i.MX25

mmc: unbreak sdhci-esdhc-imx on i.MX25

commit b89152824f993a9572b47eb31f4579feadeac34c upstream.

This was broken by me in 37865fe91582582a6f6c00652f6a2b1ff71f8a78
("mmc: sdhci-esdhc-imx: fix timeout on i.MX's sdhci") where more
extensive tests would have shown that read or write of data to the
card were failing (even if the partition table was correctly read).

Signed-off-by: Eric Bénard <eric@eukrea.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>