The patch to support SDHC DMA read for iMX51 WinCE6.0 EBoot

Attached is the SDHC DMA read supported patch, it is based on WCE600_MX51_ER_1104, it was verified on iMX51 EVK board. The SDHC DMA read can reduce the NK copy time, in this way it can speed up the WinCE boot.