mmc: Fix interpretation of MMC_CMD_ALL_SEND_CID

The interpretation of the data returned by the MMC_CMD_ALL_SEND_CID
command was incorrect with respect to the JEDEC Standard No. 84-A441.

This change makes the interpretation correct with respect to the
defined fields of the CID register.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Taylor Hutt <thutt@chromium.org>
Signed-off-by: Andy Fleming <afleming@freescale.com>