The core support for NAND booting is there already, so this patch
is pretty straightforward.

There is one trick though: top level Makefile expects nand_spl to
be in nand_spl/board/$(BOARDDIR), but we can fully reuse the code
from mpc8313erdb boards, and so to not duplicate the code we just
symlink nand_spl/board/freescale/mpc8315erdb to mpc8313erdb.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>

o silence make during ln echo
o update documentation
o and avoid:

$ ./MAKEALL MPC8315ERDB_NAND
Configuring for MPC8315ERDB board...
sdram.o: In function `fixed_sdram':
/home/r1aaha/git/u-boot/nand_spl/board/freescale/mpc8313erdb/sdram.c:72: undefined reference to `udelay'

by renaming udelay -> __udelay in the spirit of commit
3eb90bad "Generic udelay() with watchdog
support".

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

1. correct the typo
2. correct the memory map for 837xerdb board

Signed-off-by: Dave Liu <daveliu@freescale.com>

The features list:
- Boot from NOR Flash
- DDR2 266MHz hardcoded configuration
- Local bus NOR Flash R/W operation
- I2C, UART, MII and RTC
- eTSEC0/1 support
- PCI host

Signed-off-by: Dave Liu <daveliu@freescale.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>

Signed-off-by: Scott Wood <scottwood@freescale.com>