mmc-omap: fix sd response type 6 vs. 1

Ignoring OMAP_MMC_STAT_CARD_ERR, treating it as if the command
completed correctly.

Signed-off-by: Ragner Magalhaes <ragner.magalhaes@indt.org.br>
Signed-off-by: Carlos Eduardo Aguiar <carlos.aguiar@indt.org.br>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>