AT91: gen_atmel_mci.c: fix bug when Slot B is used

Signed-off-by: Reinhard Meyer <u-boot@emk-elektronik.de>
diff --git a/drivers/mmc/gen_atmel_mci.c b/drivers/mmc/gen_atmel_mci.c
index fa4df99..2984d64 100644
--- a/drivers/mmc/gen_atmel_mci.c
+++ b/drivers/mmc/gen_atmel_mci.c
@@ -308,6 +308,7 @@
 	writel(MMCI_BIT(SWRST), &mci->cr);	/* soft reset */
 	writel(MMCI_BIT(PWSDIS), &mci->cr);	/* disable power save */
 	writel(MMCI_BIT(MCIEN), &mci->cr);	/* enable mci */
+	writel(MMCI_BF(SCDSEL, MCI_BUS), &mci->sdcr);	/* select port */
 
 	/* Initial Time-outs */
 	writel(0x5f, &mci->dtor);