mmc: sdhci high speed support

The SDHCI spec implies that is is incorrect to set a clock
frequency above 25 MHz without setting the high speed bit.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/drivers/mmc/sdhci.h b/drivers/mmc/sdhci.h
index 72a6793..f9d1a0a 100644
--- a/drivers/mmc/sdhci.h
+++ b/drivers/mmc/sdhci.h
@@ -71,6 +71,7 @@
 #define SDHCI_HOST_CONTROL 	0x28
 #define  SDHCI_CTRL_LED		0x01
 #define  SDHCI_CTRL_4BITBUS	0x02
+#define  SDHCI_CTRL_HISPD	0x04
 
 #define SDHCI_POWER_CONTROL	0x29
 #define  SDHCI_POWER_ON		0x01
@@ -138,6 +139,7 @@
 #define  SDHCI_CLOCK_BASE_SHIFT	8
 #define  SDHCI_MAX_BLOCK_MASK	0x00030000
 #define  SDHCI_MAX_BLOCK_SHIFT  16
+#define  SDHCI_CAN_DO_HISPD	0x00200000
 #define  SDHCI_CAN_DO_DMA	0x00400000
 #define  SDHCI_CAN_VDD_330	0x01000000
 #define  SDHCI_CAN_VDD_300	0x02000000