sdhci: make sure to clear the error interrupt

The controller has a bit indicating that one of the higher bits (the
error bits) are set. A previous bug caused this bit to be masked, but
since that bug has been fixed we have to clear it explicictly.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 7400f4b..a6c8704 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -107,6 +107,7 @@
 #define  SDHCI_INT_CARD_INSERT	0x00000040
 #define  SDHCI_INT_CARD_REMOVE	0x00000080
 #define  SDHCI_INT_CARD_INT	0x00000100
+#define  SDHCI_INT_ERROR	0x00008000
 #define  SDHCI_INT_TIMEOUT	0x00010000
 #define  SDHCI_INT_CRC		0x00020000
 #define  SDHCI_INT_END_BIT	0x00040000