1. Add nand flash drivers,support K9F5608.
   K9F5608UOC stand at bank1, pin mapped as follow
   PC0-->RB, PC1-->CE, PC2-->CLE, PC3-->ALE
1. Advance fix packet too big while transfer image
2. Define a large SDRAM (16M) size to fit HY57v281620
3. Assigned new address to TEXT_BASE with the one (0x0c300000)
   nearly end of SDRAM
4. Enable command line auto complete and edit