fsl_esdhc: Use mmc_set_clock to set initial speed

After booting the u-boot, and first using some SD card (such as Sandisk 2G SD
card), because the field 'clock' of struct mmc is zero, this will cause
the read transfer is always active and SDHC DATA line is always active,
therefore, driver can't handle the next command.

Therefore, we use mmc_set_clock to setup both the data structure and HW
to the initial clock speed of 400000Hz.

Signed-off-by: Jerry Huang <Chang-Ming.Huang@freescale.com>
Tested-by: Stefano Babic <sbabic@denx.de>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/include/mmc.h b/include/mmc.h
index 9f94f42..74c0b1d 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2008, Freescale Semiconductor, Inc
+ * Copyright 2008,2010 Freescale Semiconductor, Inc
  * Andy Fleming
  *
  * Based (loosely) on the Linux code
@@ -280,6 +280,7 @@
 int mmc_initialize(bd_t *bis);
 int mmc_init(struct mmc *mmc);
 int mmc_read(struct mmc *mmc, u64 src, uchar *dst, int size);
+void mmc_set_clock(struct mmc *mmc, uint clock);
 struct mmc *find_mmc_device(int dev_num);
 int mmc_set_dev(int dev_num);
 void print_mmc_devices(char separator);